HISTORICAL
DEVELOPMENT of
INTERNATIONAL LAW
Why international law
originated
International Law originated from
 1) the establishment of peace and alliance
 2) the termination of a state of aggression
 3) state’s territorial integrity
 4) creating some political alliances to contain an over-powerful
empire or forming a state of subservience between states
 5) controlling violence and enhancing friendship
 6) the need for a prospering and expanding empire and the
limitedness of the jus civile gave birth and rapid growth of the jus
gentium (the Roman international law).
The Middle Ages
 The middle ages were characterized by the supreme
authority of the organized Church and the strict control
stemming from this religious-political mixture of
command.
 A new concept formulated that international
communities should be constituted by secular nation-
states with characters of :
 Independence
 Sovereignty
 competition.
The Emergence of Modern International
Law
 From 15th to 18th centuries, the embryo of modern
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international law emerged. Many international school and
famous scholars appeared. Such as Hugo Grotius.
Naturalist school & Positivist school emerged
Both the naturalist school & positivist school insisted no
interference was allowed in state’s internal affairs.
Every sovereign state shall respect each other’s diplomatic
immunity and equality.
A new doctrine of equality of states was introduced into
international law that regardless how a state was, large or
small, weak or powerful, it was equal to any other state in
terms of sovereignty.
The 19th Century
 Many Features
 self-determination
 Democracy
 state equality and realization of international
responsibility
 racial superiority and desires for gaining through
aggressive approaches
 the Industrial Revolution and breakthroughs in science
and technology propelled Western influence and idea of
European supremacy throughout the world.
The 19th Century
 positivist theories
·dominated the 19th with the rapid expansion of the rules of international law
and with the gradual but progressive development of modern international
system.
·according to the positivist theory, international law depended upon the will of
the sovereign states.
·with the development of international agreements, customs and regulations,
positivist theorists were in a position to solve the problem in international law,
and as a result 2 school of thought emerged. Monists & Dualists.
·the monists claimed that there was only one fundamental principle. 个人行为
·the dualists maintained that international law and domestic law existed on
separate planes. International law should be based upon agreements
between states.
MEANING, SUBJECTS AND
INTERNATIONAL LAW


DEVELOPMENT OF
Development: - Certain rules of different branches of
international law have existed since time immemorial, especially
with the Indian, Chinese, Roman, Greek and Arab/Islamic empires
before western Europe.
In terms of the development of international law, it is true that
contemporary rules of international law were fashioned out by the
European nations (or the so-called 1st World) in the 19th and early
part of the 20th Centuries.
In the course of its development especially in the mid-20th
Century/post 2nd World War when the newly independent African,
Asian and Latin American states started coming on board of
international life, they have no option but to start challenging
some of the principles and concepts or rules of international law
which never took their political, economic, social and
developmental interests into consideration. This was simply
because they were then colonial territories of the 1st World.
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RELATIONSHIP BETWEEN INTERNATIONAL LAW AND
MUNICIPAL LAW
This relationship is of practical and theoretical
significance in international law and can be appreciated from
3 perspectives: - Dualism, Monism and Nihilism.
 Dualist doctrine: States belonging to the dualist school of
thought hold the view that international and municipal laws
are 2 different laws in character and scope. Hence
international law rules and principles cannot apply directly in
the municipal courts of a dualist state without first
undergoing the process of specific adoption by or
incorporation into national law.
 All common law countries are dualist states.
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RELATIONSHIP BETWEEN INTERNATIONAL LAW AND
MUNICIPAL LAW
 Monism: - Protagonists of this doctrine assert the
superiority of international law over municipal law even
within the sphere of national law itself. Hence upon
ratification of a treaty, it becomes operative and enforceable
nationally.
 Largely embraced by civil law jurisdictions
 E.g., all French-speaking States.
 Nihilism: - Protagonists of this doctrine assert the absolute
supremacy of municipal law over international law in the
event of any conflict on a given subject matter.
 The USA is a typical example.
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International Law Today
 The League of Nations
 The United Nations Organization
 The Permanent Court of International Justice
 The International Court of Justice
International Law developed with the development
of international organizations/institutions
International Law Today
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Some principles
non-intervention in internal affairs
territorial integrity
nonuse of force
equality of voting in the UN General Assembly
 Today international law has not only expanded its jurisdictional
scope to embrace newly established states, but also extended
itself to include individuals, groups, multinational corporations
and international organizations within its jurisdiction.
 international law has been progressing to tackle new problems
in a wider range, which has never been covered before.
INTRODUCTION OF
INTERNATİONAL LAW
International Law
 Public International Law;
- is the body of rules of conduct,
- which are binding the members of the international
community,
- in their relations with each other.
 International Law;
- is concerned traditionally with general principles and
specific rules,
- regulating relations between states.
 It should be noted that;
- there are other members of international community,
- such as international organizations.
International Law
 Individuals;
- have become increasingly recognized as participants
and subjects of international law.
 International Law;
- also imposes criminal responsibility,
- for serious violations of humanitarian law governing
armed conflicts.
International Law
 The activities of international organizations;
- cover various fields,
- from culture and turism to military and economic cooperation.
 Some of these organizations;
- are universal, like the United Nations.
- others are regional, as the Council of Europe.
- Other examples include NATO, IMF, WTO.
International Law
 In international law;
- the legal procedure is quite different,
- because, there is no single central supranational authority,
- to make rules and enforce them,
- through the use of sanctions in a systematic and continous
manner.
 The rules of international law;
- have their own sources,
- which are different from those of municipal law.
SOURCES OF
INTERNATIONAL
LAW
International Law
 Main sources of international law;
- are defined in Art.38/1 of the “Statute of the International
Court of Justice.”
 ICJ;
- is to apply the following laws to the cases brought before it;
1. International Conventions, whether general or particular,
establishing rules, recognized by the litigant states.
2. International custom, as the evidence of a general practice,
3. General principles of law, recognized by civilized nations,
4. Judicial decisions and teachings, of the most qualified
various nations, as subsidiary means for the determination of
rules of law.
Today, there are 8 sources of international law divided into traditional
and non-traditional sources.
5 Traditional Sources
Subsidiary (2)
Principal (3)
Treaty
Customary
Rules of
International
Law
General
Principles of
Law
Judicial
Decisions
Writings of the
most highly
qualified Scholars
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SOURCES OF INTERNATIONAL LAW (Cont’d)
According to Article 38(1) of the Statute of the ICJ the
five traditional sources recognized under international law
are as follows: 
Treaty: - means an international agreement concluded
between states or parties – may be bilateral /multilateral
and may be called any of the following names/types: charter, convention, covenant, Protocol.

Effect of ratification of a treaty.

Effect of domestication of a treaty into national law
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International Law
 Written agreements;
- are generally called treaties and conventions,
- Other terms exist, such as pacts, covenants, charters,
protocols, etc…
- They are similar to the texts of the law of contracts in
municipal law.
 Written agreements;
- are not imposed on states by some supranational
legislative body.
- There is no international parliament, possessing legislative
powers, to impose international law on individual states.
International Law
 Types of International agreements;
- All states are parties to some agreements. (UN Charter)
- Some conventions have a regional nature, and open only
to a certain group of states.
- Many agreements are concluded only between two states.
 Agreements;
- are called bilateral, if they are between just two parties.
- are called multilateral, if they are between more than two
parties.
SOURCES OF INTERNATIONAL LAW (Cont’d)
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Custom: - is evidence of a general practice accepted as
law. This can be established by the existence of
bilateral/multilateral relations between states based on
the belief of the existence of a legal obligation (i.e.
opinion juris-legal belief or state practice). E.g., the 4
Geneva Conventions and the Hague Conventions (on
conduct of war, treatment of prisoners of war etc) and the
entire provisions of the Universal Declaration of Human
Rights of 1948.
General Principles of Law: - Are principles of equity and
rules emanating from justice and considerations of public
policy.
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SOURCES OF INTERNATIONAL LAW (Cont’d)

Examples of General Principles of Law
a) The principle of good faith (Pacta Sunt Servanda). This is
found expressed in Article 26 of the 1969 Vienna
Convention on the Law of Treaties (which came into
force on 27 January 1980) and is to the effect that every
treaty in force is binding upon the parts to it and must be
performed by them in good faith. As such a party may
not unilaterally free itself from the engagements of a
treaty, or modify the stipulations thereof, except by the
consent of the contracting parties, through a friendly
understanding.
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 The principle of abuse of rights: - is to the effect that states must
exercise their rights in a manner compatible with their various
obligations arising either from treaties or from the general law. This
principle can be illustrated in the Corfu channel case (ICJ Report, 1949,
p. 22) where the ICJ concluded that: “No state may utilize its territory
contrary to the rights of other states.
 The latter states: - “states, have, in accordance with the UNC and the
principles of international law, the sovereign right to exploit their own
resources pursuant to their own environmental and developmental
policies and the responsibilities to ensure that activities within their
jurisdiction or control do not cause damage to the environment of
other states or of areas beyond the limits of national jurisdiction.
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SOURCES OF INTERNATIONAL LAW (Cont’d)
 Judicial Decisions: - of international courts and tribunals
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such as the
ICJ
ICC
ICTY
ICTR
UN Special Court for Sierra-Leone
European Court of Justice
European Court of Human Rights
African Court of Human Rights
Inter-American Court of Human Rights
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SOURCES OF INTERNATIONAL LAW (Cont’d)
 Writings of Scholars/Jurists/Commentators: - of long
standing research and experience rooted in their fields of
specialization are relied upon for trustworthy evidence of
what the law really is and not what it ought to be.
Non Traditional Sources
Pre-emptory Norms
Resolutions of International
Organizations
Non-Binding Standards
(Soft Law)
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SOURCES OF INTERNATIONAL LAW (Cont’d)
The three non-traditional sources of international law are:  Pre-emptory Norms: - are final/absolute/mandatory norms
recognized and accepted by the international community as
a whole from which no derogation is allowed by any treaty or
municipal law, else void.
 Also known as Rules of Jus Cogens.
 E.g., the absolute prohibition of torture and slavery or the general
norm prohibiting the use of force in the internal affairs of a sovereign
state or the promotion and protection of the right to life.
 Resolutions
of public international Organisations/
Institutions: - UN, AU, EU, ECOWAS etc resolutions on given
subject matters constitute a source of international law with
respect to the matters in question.
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SOURCES OF INTERNATIONAL LAW (Cont’d)
 Non-binding standards (Soft law): - Are those rules of conduct,
statements, principles, policies not intended to be legally binding
but are expressions of intent by the international or regional
community in a given topical/critical issue of interest to all.
 Examples of Non-Binding Standards
 The 1972 Stockholm Declaration on the Human Environment resulted
from the UN Conference on the Environment designed to deal with
questions surrounding the management and protection of the
environment and its relationship with humans. 130 states participated at
the conference where the recommendation for institutional
arrangement resulted in the UN General Assembly’s establishment of
UNEP.
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SOVEREIGNTY IN INTERNATIONAL LAW
 Sovereignty as a concept in international law is
constitutive of the following: -
 an expression of statehood: - having possessed all the
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characteristics and being so recognized as an independent
state by others;
an indication of preservation of national identity and hard
won independence;
an expression of self-determination covering 2 aspects: internal and external;
internal self-determination is about the right of people to
choose their socio-political and economic systems and the
extent of their political participation in government;
it is largely against colonialism, neo-colonialism, apartheid
and for sovereignty over their territory, linguistic, sociocultural, ethnic and religious interests;
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CONCEPT OF SOVEREIGNTY IN INTERNATIONAL LAW
(Cont’d)

External self-determination is about a right against foreign economic exploitation
of natural resources: - it is a right to exploit, dispose of, utilize or deal with natural
resources in any way the state feels necessary for the common good of all.
 The above are expressly covered by the 1960 UN Declaration on the granting of
independence to colonized countries; Article 55 UN Charter, 1945 emphasises the
importance of economic self-determination to remove oppression, injustice,
inequity and to promote peace, stability and development; Article 1 of the same
charter seeks to promote friendly relations and socio-economic and cultural
development of nations; Article 1 of both the ICCPR and ICESCR of 1966 re-echoed
the right to self-determination as a fundamental right of a people; Articles 2, 21-24
of the African Charter on Human and Peoples’ Rights provide for norms to
eradicate all forms of colonialism and the promotion of internal and external selfdetermination as a developmental right of African peoples.
 About assumption of state responsibility in international life because liability
exists for failure to observe/discharge obligations imposed by rules of international
law (especially treaty obligations).
 Is about non-intervention in the internal affairs of sovereign states as generally
prohibited by international law except in self-defence and on the authorization of
the UN Security council for the maintenance of international peace and security.
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CONCEPT OF SOVEREIGNTY IN INTERNATIONAL LAW
(Cont’d)
 However, in international law and practice today, the claim
of sovereignty is not absolute due to the following
acknowledged exceptions to the general rule prohibiting
non-intervention in internal affairs of sovereign states;
 For collective security: - doctrine that emerged in the late 1980s after
the end of the cold war and when the perception of security changed
from military and political issues to socio-economic, developmental,
environmental, human rights and humanitarian issues as well as
gender;
 Hence intervention by the use of force is allowed for collective
security in a sovereign state on the following grounds:  Where a regional or ethnic or political conflict or conflict over scarce
resources are deemed potentially destabilizing on a sub-regional, regional
or global scale;
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CONCEPT OF SOVEREIGNTY IN INTERNATIONAL LAW
(Cont’d)
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Where the conflict is capable of endangering the lives of civilians and
non-combatant population;
Where the conflict results in massive displacement of civilian
population either as IDPs or refugees;
Where the conflict results in gross or massive human rights violations
constituting genocide or crimes against humanity; or in order to
protect human rights;
Where a country’s government is universally recognized to have
collapsed leading to lawlessness and possible loss or injury to human
lives and property;
Intervention is also allowed on humanitarian grounds in order to
assist the victims of humanitarian crises;
In order to enforce a treaty/ in defence of democracy/ in the fight
against terrorism;
The Liberian, Sierra-Leonean, Rwandan, Bosnian, Kosovan conflicts
and those of the Sudan-Darfur, Somalia, and Congo etc are typical
examples of the above justification.
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CONCEPT OF HUMAN RIGHTS IN INTERNATIONAL LAW
The scope of this lecture is restricted to the
following branches of public International Law.
1. International Human Rights Law (IHRL)
Meaning and Scope: - IHRL is that branch of public
international law that aims at protecting the
internationally guaranteed rights of individuals and
groups against violations by state etc.
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BRANCHES OR FIELDS OF PUBLIC INTERNATIONAL LAW
(Cont’d)
Scope of Internationally Guaranteed Human Rights
1st Generation
Civil & Political Rights
Refugees &
IDPs
Women
2nd Generation
Economic, Social &
Cultural Rights
Persons Living
with HIV-AIDS
3rd Generation
Rights of Vulnerable
Group
Children
Environmental,
Developmental Rights
Minorities
Disabled
Persons
Ethnic, Linguistic, Cultural, Political,
Religious, Racial, Sexual
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THANK YOU
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