The plague in Tournai
New light on the
Black Death
London plague burials
Fundación
Ramón Areces
Bruce M. S. Campbell
Professor of Medieval Economic History,
The Queen’s University of Belfast
Y. Pestis phylogenetic tree
b.m.campbell@qub.ac.uk
Today, plague is a global disease with 1,000-2,000
cases a year reported to the World Health Organisation.
Plague cases and deaths are both greatest in subSaharan Africa.
Today, plague is a global disease with 1,000-2,000
cases a year reported to the World Health Organisation.
Plague cases and deaths are both greatest in subSaharan Africa.
Fear of plague derives from history’s 3 great
pandemics:
 AD 541: First Pandemic (Justinianic Plague) – devastated
the Byzantine Empire.
 1346: Second Pandemic (Black Death) – spread
throughout the Known World and killed 30%-40% of a
European population of c.80 million (24-32m.).
 1855: Third Pandemic – broke out in Yunnan Province of
China; spread worldwide; the first to be medically
analysed and diagnosed.
The impact of the Black Death and its sequel plagues
upon European populations was massive and long
lasting:
125
Indexed population
(100 = AD 1300)
100
75
50
Europe (100 = 79m)
25
England (100 = 4.75m)
Italy north-centre (100 = 7.75m)
0
1250
1300
1350
1400
Decades
1450
1500
Economic output also contracted almost everywhere,
as plague killed both producers and consumers:
140
Indexed GDP (100 = mean 1340s)
England
Italy
120
Spain
100
80
60
40
1300
1350
1400
Quinquennia
1450
In terms of GDP per head, loss of numbers proved to
be beneficial for England and Holland, a mixed
blessing for Italy, and a significant setback for Spain:
GDP per head
(100 = mean 1310s-1340s)
175
150
125
100
75
Indexed GDP per head
England
Spain
Italy
Holland
50
1300
1350
1400
Decades
1450
In England the sudden scarcity of labour triggered the
single greatest inflation in labourers’ daily wage rates
on historical record.
200
Black
Death
Nominal wages of farm workers
as % of previous 31 years
(source: Gregory Clark)
% wage
175
Napoleonic
Wars
Tudor price
inflation
150
125
100
75
Reformation
50
1250
1350
1450
1550
Years
1650
1750
1850
In Siena work on the vast
new nave being added
to the cathedral of
Santa Maria Assunta
was abandoned and
never resumed.
In Siena work on the vast
new nave being added
to the cathedral of
Santa Maria Assunta
was abandoned and
never resumed.
In neighbouring
Florence, work on
Giotto’s new
Campanile was
suspended at the
second stage and only
resumed after an interval
of 10 years.
 Construction activity
almost ceased.
 Farmland was
abandoned.
60
Indexed wage / Cumulative start dates
Across Europe woodland
regenerated as:
50
40
30
20
PRE-PLAGUE
POST-PLAGUE
Irish
Net cumulative
total oaks started
English
Real farm wage
rate (5 yr m.a.)
10
0
1300
-10
1325
DEPLETION
1350
1375
REGENERATION
Epidemiologically,
demographically,
environmentally, economically
and culturally, the Black Death
was a watershed historical event.
What
disease
was it?
The list of suspects has
included:
 bubonic plague
(Shrewsbury, 1971, and many
others)
 anthrax
(Twigg, 1984)
 a viral haemorrhagic fever
(Scott & Duncan, 2001)
 a now extinct disease
(Cohn, 2002)
 biological fallout from an extraterrestrial impact in Jan. 1348
(Baillie, 2006)
 something else entirely . . . . .
PNAS
Proceedings of the National Academy of Sciences
of the United States of America
November 2000, Volume 97, no. 23, pp. 12800-12803.
Claimed to have identified the DNA
of Yersinia pestis (bubonic plague)
in the dental pulp of medieval
plague burials at Montpellier in
southern France.
October 7, 2010
STOP PRESS
aDNA analysis proves the Black Death
was vector-borne Yersinia Pestis after all!
Since 2010 confirmation that the Black Death was
indeed bubonic plague, i.e. Yersinia pestis, has come
from aDNA analysis of dental remains from datable 14thcentury plague burials in 5 Western European countries:
1. France (Saint Laurent-de-la-Cabrerisse)
2. Italy (Parma & Venice)
3. Southern Germany (Augsburg)
4. The Netherlands (Bergen op Zoom)
5. England (Hereford and East Smithfield, London).
A Rapid Diagnostic Test has yielded complementary
results.
Crucially, these aDNA results have been obtained in
separate laboratories by independent teams of scientists.
Meanwhile, a 23-strong team of biologists & geneticists
has reconstructed the Yersinia pestis phylogenetic tree:
Giovanna Morelli and 22 others (2010), ‘Yersinia pestis genome
sequencing identifies patterns of global phylogenetic diversity’,
Nature Genetics 42 (12), 1140-43.
This has since been amplified and redefined in a key
paper by Yujun Cui and 32 others to show where the
Black Death genomes fit in:
‘Population structure of Y. pestis revealed by core genome
SNP analysis’, PNAS 110 (2), 2013, 577-82.
Genetic reconstruction has yielded the following
key conclusions:
1. Y. pestis evolves clonally; small mutations
differentiate plague’s different branches
(polytomies) and strains.
2. Fresh polytomies are prone to emerge during major
epizootics/panzootics.
3. Almost all strains are capable of infecting and
killing humans.
4. There is nothing to suggest that the genomes
responsible for the Black Death were more
dangerous than any others.
5. The 1st and 2nd Pandemics arose from different
crossovers of the pathogen from animals to humans.
Genetic reconstruction has yielded the following
key conclusions:
6. The plague genome embodies its own evolutionary
history and pattern of spread.
7. Individual strains tend to be country-specific.
8. Regions where plague has existed longest tend to
exhibit the greatest genomic diversity and the
presence of the earliest genotypes.
Genetic reconstruction
has
yielded
The Qinghai-Tibet Plateau
of Western
China the following
key conclusions:
6. The plague genome embodies its own evolutionary
history and pattern of spread.
7. Individual strains tend to be country-specific.
8. Regions where plague has existed longest tend to
exhibit the greatest genomic diversity and the
presence of the earliest genotypes.
9. Geographically, the semi-arid Qinghai-Tibet Plateau
of Western China appears to have been the ultimate
origin of the Black Death.
Genetic reconstruction has yielded the following
key conclusions:
6. c.1268/1282
The plague genome embodies its own evolutionary
history and pattern of spread.
7. Individual strains tend to be country-specific.
8. Regions where plague has existed longest tend to
exhibit the greatest genomic diversity and the
presence of the earliest genotypes.
9. Geographically, the semi-arid Qinghai-Tibet Plateau
of Western China appears to have been the ultimate
origin of the Black Death.
10.Temporally, the Black Death genome emerged
during a biological ‘big bang’ shortly after 1268 (Cui
and others, 2013) or 1282 (Bos and others, 2011).
Qinghai-Tibet is one of
several regions where
permanent (enzootic)
reservoirs of plague
exist among groundburrowing and
hibernating sylvatic
rodents, in this case
great gerbils :
The plague cycle:
The transformation
of plague from an
enzootic disease
among maintenance
hosts of wild-rodents
to a fast-spreading
and deadly human
pandemic entailed
at least 4, and
possibly 5, stages:
1
The plague cycle:
Stage 1 –
enzootic plague
2
The plague cycle:
Stage 2 –
epizootic plague
3
The plague cycle:
Stage 3 –
panzootic plague
4
350
The plague cycle:
Stage 4 –
Zoonotic plague
Number of deaths
300
250
200
Givry (Burgundy),
1348
Penrith (N England),
1597-9
150
100
50
0
A S O N D J F M A M J J A S O N D J F
Month
5
The plague cycle:
Stage 5 –
Pandemic plague
The plague cycle:
Historically, climatic
conditions in Arid
Central Asia have
exercised a powerful
influence upon the
incidence of plague,
either lowering or
raising the risks of
enzootic plague
becoming amplified
into epizootic plague
etc.
The Oslo plague team led by Nils Chr. Stenseth has
investigated and established a link between climate,
gerbil populations, and outbreaks of Yersinia pestis in the
water-limited steppe grasslands of southern Kazakhstan:
Drought lowered the risks of plague outbreaks by
depressing biomass output, food availability, and gerbil
populations and, at the same time, inhibiting flea activity.
1270s-1330s
Wolf Minimum
Indexed value
(100 = average 1000-1500)
Sunspot numbers from dendro
Total Solar Irradiance from ice cores
150
100
Medieval Solar
Maximum 1070s1260s
50
800s
900s
1000s
1100s
Decades
1200s
1300s
These were the conditions that prevailed in Arid Central
Asia throughout the Medieval Solar Maximum between
the end of the 1st Pandemic in the the 8th century and
start of the 2nd Pandemic in the 14th century.
Drought lowered the risks of plague outbreaks by
depressing biomass output, food availability, and gerbil
populations and, at the same time, inhibiting flea activity.
< DRIER Index WETTER >
1270s-1330s
Wolf Minimum
Total Solar Irradiance from ice cores
1.0
Increasing aridity
0.5
0.0
900
1000
1100
1200
1300
1400
-0.5
800s
-1.0
Arid Central Asia moisture index
Decades
These were the conditions that prevailed in Arid Central
Asia throughout the Medieval Solar Maximum between
the end of the 1st Pandemic in the the 8th century and
start of the 2nd Pandemic in the 14th century.
Onset of pluvial conditions increased the risks of plague
outbreaks by raising biomass output, food availability,
and gerbil populations and, at the same time, stimulating
flea activity.
Total Solar Irradiance from ice cores
1270s-1330s
Wolf Minimum
< DRIER Index WETTER >
1.0
0.5
0.0
900
1000
1100
1200
-1.0
1400
Increasing
humidity
-0.5
800s
1300
Arid Central Asia moisture index
Decades
These were the conditions that prevailed in Arid Central
Asia following onset of the Wolf Solar Minimum and
especially from the 14th century as part of a global
reorganization of atmospheric circulation.
< DRIER Moisture/Precipitation index WETTER >
1.0
0.5
0.0
900
1000
1100
1200
-0.5
-1.0
Decades
1300
1400
Changes in atmospheric circulation across
inner Eurasia
Arid Central Asia moisture index
Morocco precipitation index
Scotland precipitation index
< DRIER Moisture/Precipitation index WETTER >
1.0
0.5
0.0
900
1000
1100
1200
-0.5
-1.0
Decades
1300
1400
Changes in atmospheric circulation across
inner Eurasia
Arid Central Asia moisture index
Morocco precipitation index
Scotland precipitation index
< DRIER Moisture/Precipitation index WETTER >
1.0
0.5
0.0
900
1000
1100
1200
-0.5
-1.0
Decades
1300
1400
Changes in atmospheric circulation across
inner Eurasia
Arid Central Asia moisture index
Morocco precipitation index
Scotland precipitation index
< DRIER Moisture/Precipitation index WETTER >
1.0
0.5
Str ong Wester lies
0.0
900
1000
1100
1200
1300
1400
Weak
Westerlies
-0.5
-1.0
Decades
Parallel changes were taking place in the
strength of the South Asian Monsoon:
Weakening
monsoon
0.50
Mega
drought
0.00
800
-0.50
850
900
950
1000
1050
1100
1150
1200
Strong monsoon
Oort
Solar
Min.
Medieval Solar Maximum
-1.00
Decades
1250
1280s drought
< DRIER
Precipitation index
WETTER >
1.00
1300
Wolf
Solar
Minimum
1350
Plague’s reactivation from an enzootic to an epizootic
state sometime after 1268/1282 coincided with an
episode
of global
climate
reorganisation:
Arid Central
Asia moisture
index
Morocco
precipitation index
Scotland precipitation index
< DRIER Moisture/Precipitation index WETTER >
1.0
0.5
0.0
900
1000
1100
1200
1300
1400
Weak
Westerlies
-0.5
-1.0
Decades
Dendrochronologies from Central Asia bring this episode
into sharper focus:
Indexed ring width
(100 = mean 1150-1349)
150
Mongolia (Siberian pine)
Tien Shan (Juniper )
NE Tibet (Juniper)
125
100
75
50
1250
1270
1290
1310
Years
1330
Dendrochronologies from Central Asia bring this episode
into sharper focus:
Indexed ring width
(100 = mean 1150-1349)
150
Mongolia (Siberian pine)
Tien Shan (Juniper )
NE Tibet (Juniper)
125
100
75
50
1250
1270
1290
1310
Years
1330
Dendrochronologies from Central Asia bring this episode
into sharper focus:
Indexed ring width
(100 = mean 1150-1349)
150
Mongolia (Siberian pine)
Tien Shan (Juniper )
NE Tibet (Juniper)
125
100
75
50
1250
1270
1290
1310
Years
1330
Dendrochronologies from Central Asia bring this episode
into sharper focus:
Indexed ring width
(100 = mean 1150-1349)
150
Mongolia (Siberian pine)
Tien Shan (Juniper )
NE Tibet (Juniper)
Mean chronology
125
100
75
50
1250
1270
1290
1310
Years
1330
Ecological stress in Arid Central Asia, generated by increased
climatic instability, appears to have ignited the epizootic that led
to the Black Death.
Mongolia (Siberian pine)
Tien Shan (Juniper )
Indexed ring width
(100 = mean 1150-1349)
150
D
R
O
U
G
H
T
125
NE Tibet (Juniper)
Mean chronology
D
R
O
U
G
H
T
D
R
O
U
G
H
T
100
75
P
L
U
V
I
A
L
P
L
U
V
I
A
L
50
1250
1270
1290
1310
Years
1330
From its source in Qinghai, as aridity eased, plague
then spread westwards across desert and mountains
to Issyk-Kul in Kirgizia:
From its source in Qinghai, as aridity eased, plague
then spread westwards across desert and mountains
to Issyk-Kul in Kirgizia:
Issyk-Kul, Kirghizia
W. Europe
Christakos, Olea &
Hwa-Lung (2007)
c.1½-6 kms per day
Messina, Sicily
1346
1338/9
1347
Kipchak Khanate /
Golden Horde
c.7 years
4,000 kms
c.1½ kms per day
Qinghai / Tibet?
c.40 years
2,000 kms
c.1 km per week
1290s?
The speed of the Black Death’s spread implies that
humans must in some way have been complicit in its
dissemination.
The Catalan World Atlas, 1375:
“the intensification of over-land caravan movement
across Asia that reached its climax under the Mongol
empires ..... affected both macro- and micro-parasitic
patterns in far-reaching ways”
The World-system of commerce c.1300 according to Janet Abu-Lughod, 1989.
Traders and travellers were material to the relentless westward
spread of the pathogen, its vectors and hosts, until the
Genoese port of Kaffa in the Crimea was reached in 1346.
“In the same year [1346], God’s punishment struck the people in the eastern lands, in
the town Ornach [on the estuary of the R. Don], and in Khastorokan, and in Sarai, and
in Bezdeh, and in other towns in those lands; the mortality was great ..... so that they
could not bury them”
(Benedictow, 2004)
Gabriele de Mussis, Michele da Piazza, Nicephoros Gregoras,
Emperor John VI & Ibn al-Wardi: Spring 1346: plague first
surfaced in the lands of the Kipchak Khanate of the Golden Horde.
The Black Death - some fresh
insights from recent research:
1. The Black Death WAS Yersinia pestis.
2. Its geographical origin was the semi-arid
Qinghai-Tibet Plateau in Western China, where its
maintenance hosts were wild gerbils and marmots.
3. Its biological re-activation from a dormant enzootic
state to a more virulent epizootic state occurred during
the closing decades of the 13th century.
4. This vital biological transformation took place under
conditions of mounting ecological stress generated by
the alternation of drought and pluvial events, as global
patterns of atmospheric circulation de-stabilized and
changed.
The Black Death - some fresh
insights from recent research:
5. Traders and travellers were instrumental
in aiding and abetting plague’s westward
spread across the interior of Eurasia.
6. Genoese mariners performed the same function once
plague reached the Black Sea coast and had crossed
over and infected commensal rodents (i.e. black rats).
7. In Europe, poverty, over crowding, high levels of
commercial activity, war, harvest failure and unusually
humid weather conditions combined to ensure that the
Black Death’s spread was rapid and its mortality heavy.
8. Further changes in plague’s hosts and vectors may have
added momentum and reach to the disease’s spread.
The Black Death - some fresh
insights from recent research:
9. The Black Death was the
product of a unique
conjuncture of biological,
climatic and human
developments.
The Black Death - some fresh
insights from recent research:
10.The fate of medieval Europeans was
intimately bound up with environmental developments taking place
6,000 kilometres to the east, in the semi-arid and
sparsely populated interior of Central Asia.
EL FIN