Collapse: How Societies Choose to Fail or Succeed (35 page)

combination of push and pull, and that was also true of the Vikings: they
were pushed by population growth and consolidation of royal power at
home, and pulled by uninhabited new lands to settle and inhabited but de
fenseless rich lands to plunder overseas. Similarly, European immigration to
North America reached its peak in the 1800s and early 1900s through a
combination of push and pull: population growth, famines, and political
oppression in Europe pushed immigrants from their homelands, while the
availability of almost unlimited fertile farmland and economic opportuni
ties in the United States and Canada pulled them.

As for why the sum of push/pull forces switched so abruptly from unat
tractive to attractive after
a.d.
793, and then subsided so quickly towards
1066, the Viking expansion is a good example of what is termed an
auto-
catalytic process.
In chemistry the term
catalysis
means the speeding-up of a
chemical reaction by an added ingredient, such as an enzyme. Some chemi
cal reactions produce a product that also acts as a catalyst, so that the speed
of the reaction starts from nothing and then runs away as some product is
formed, catalyzing and driving the reaction faster and producing more product which drives the reaction still faster. Such a chain reaction is
termed
autocatalytic,
the prime example being the explosion of an atomic
bomb when neutrons in a critical mass of uranium split uranium nuclei to
release energy plus more neutrons, which split still more nuclei.

Similarly, in an autocatalytic expansion of a human population, some
initial advantages that a people gains (such as technological advantages)
bring them profits or discoveries, which in turn stimulate more people to
seek profits and discoveries, which result in even more profits and discov
eries stimulating even more people to set out, until that people has filled up
all the areas available to them with those advantages, at which point the
autocatalytic expansion ceases to catalyze itself and runs out of steam. Two
specific events set off the Viking chain reaction: the
a.d.
793 raid on Lindis-
farne Monastery, yielding a rich haul of booty that in the following year
stimulated raids yielding more booty; and the discovery of the unpopulated Faeroe Islands suitable for raising sheep, leading to the discovery of larger
and more distant Iceland and then of still larger and more distant Green
land. Vikings returning home with booty or with reports of islands ripe for
settlement fired the imagination of more Vikings to set out in search of
more booty and more empty islands. Other examples of autocatalytic ex
pansions besides the Viking expansion include the expansion of ancestral Polynesians eastwards over the Pacific Ocean beginning around 1200
b.c.,

and of Portuguese and Spaniards over the world beginning in the 1400s and
especially with Columbus's "discovery" of the New World in 1492.

Like those Polynesian and Portuguese/Spanish expansions, the Viking
expansion began to fizzle out when all areas readily accessible to their ships
had already been raided or colonized, and when Vikings returning home
ceased to bring stories of uninhabited or easily raided lands overseas. Just as two specific events set off the Viking chain reaction, two other events sym
bolize what throttled it. One was the Battle of Stamford Bridge in 1066, cap
ping a long series of Viking defeats and demonstrating the futility of further
raids. The other was the forced abandonment of the Vikings' most remote
colony of Vinland around
a.d.
1000, after only a decade. The two preserved
Norse sagas describing Vinland say explicitly that it was abandoned because
of fighting with a dense population of Native Americans far too numerous
to be defeated by the few Vikings able to cross the Atlantic in ships of those
times. With the Faeroes, Iceland, and Greenland already full of Viking set
tlers, Vinland impossibly dangerous, and no more discoveries of uninhabited Atlantic islands being made, the Vikings got the point that there were
no longer any rewards to greet pioneers risking their lives in the stormy
North Atlantic.

When immigrants from overseas colonize a new homeland, the lifestyle that
they establish usually incorporates features of the lifestyle that they had
practiced in their land of origin
—a "cultural capital" of knowledge, beliefs,
subsistence methods, and social organization accumulated in their homeland. That is especially the case when, as true of the Vikings, they occupy
a land that is originally either uninhabited, or else inhabited by people with
whom the colonists have little contact. Even in the United States today, where
new immigrants must deal with a vastly more numerous established Ameri
can population, each immigrant group still retains many of its own distinc
tive characteristics. For instance, within my city of Los Angeles there are big
differences between the cultural values, educational levels, jobs, and wealth
of recent immigrant groups such as Vietnamese, Iranians, Mexicans, and
Ethiopians. Different groups here have adapted with different ease to Ameri
can society, depending in part on the lifestyle that they brought with them.

In the case of the Vikings, too, the societies that they created on the North Atlantic islands were modeled on the continental Viking societies
that the immigrants had left behind. That legacy of cultural history was

especially important in the areas of agriculture, iron production, class structure, and religion.

While we think of Vikings as raiders and seafarers, they thought of
themselves as farmers. The particular animals and crops that grew well in southern Norway became an important consideration in overseas Viking
history, not only because those were the animal and plant species available
for Viking colonists to carry with them to Iceland and Greenland, but also
because those species were involved in the Vikings' social values. Different
foods and lifestyles have different status among different peoples: for in
stance, cattle ranked high but goats ranked low in the values of ranchers in the western United States. Problems arise when the agricultural practices of
immigrants in their land of origin prove ill-matched to their new home
land. Australians, for example, are struggling today with the question of
whether the sheep that they brought with them from Britain have really
done more harm than good in Australian environments. As we shall see, a
similar mismatch between what was suitable in old and new landscapes had
heavy consequences for the Greenland Norse.

Livestock grew better than crops in Norway's cool climate. The livestock
were the same five species that had provided the basis of Fertile Crescent and European food production for thousands of years: cows, sheep, goats,
pigs, and horses. Of those species, the ones considered of highest status by
Vikings were pigs bred for meat, cows for milk products such as cheese, and
horses used for transport and prestige. In Old Norse sagas, pork was the
meat on which warriors of the Norse war god Odin feasted daily in Valhalla
after their deaths. Much lower in prestige, but still useful economically, were
sheep and goats, kept more for milk products and wool or hair than for meat.

Counts of bones in an archaeologically excavated garbage heap at a 9th-
century chieftain's farm in southern Norway revealed the relative numbers
of different animal species that the chieftain's household consumed. Nearly
half of all livestock bones in the midden were of cows, and one-third were of the prized pigs, while only one-fifth belonged to sheep and goats. Pre
sumably an ambitious Viking chief setting up a farm overseas would have
aspired to that same mix of species. Indeed, a similar mix is found in
garbage heaps from the earliest Viking farms in Greenland and Iceland.
However, the bone proportions differed on later farms there, because some of those species proved less well adapted than others to Greenland and Ice
land conditions: cow numbers decreased with time, and pigs almost van
ished, but the numbers of sheep and goats increased.

The farther north that one lives in Norway, the more essential it be
comes in the winter to bring livestock indoors into stalls and to provide
them with food there, instead of leaving them outdoors to forage for themselves. Hence those heroic Viking warriors actually had to spend much of
their time during the summer and fall at the homely tasks of cutting, dry
ing, and gathering hay for winter livestock feed, rather than fighting the bat
tles for which they were more famous.

In areas where the climate was mild enough to permit gardening,
Vikings also grew cold-tolerant crops, especially barley. Other crops less im
portant than barley (because they are less hardy) were the cereals oats,
wheat, and rye; the vegetables cabbage, onions, peas, and beans; flax, to
make linen cloth; and hops, to brew beer. At sites progressively farther north
in Norway, crops receded in importance compared to livestock. Wild meat
was a major supplement to domestic livestock as a source of protein
—
especially fish, which account for half or more of the animal bones in Nor
wegian Viking middens. Hunted animals included seals and other marine
mammals, reindeer and moose and small land mammals, seabirds taken on
their breeding colonies, and ducks and other waterfowl.

Iron implements discovered at Viking sites by archaeologists tell us that
Vikings used iron for many purposes: for heavy agricultural tools such as
plows, shovels, axes, and sickles; small household tools, including knives, scissors, and sewing needles; nails, rivets, and other construction hardware; and, of course, military tools, especially swords, spears, battle-axes, and ar
mor. The remains of slag heaps and charcoal-producing pits at iron-
processing sites let us reconstruct how Vikings obtained their iron. It was not mined on an industrial scale at centralized factories, but at small-scale
mom-and-pop operations on each individual farm. The starting material
was so-called bog iron widespread in Scandinavia: i.e., iron oxide that has become dissolved in water and then precipitated by acidic conditions or bacteria in bogs and lake sediments. Whereas modern iron-mining compa
nies select ores containing between 30 and 95% iron oxide, Viking smiths
accepted far poorer ores, with as little as 1% iron oxide. Once such an "iron-
rich" sediment had been identified, the ore was dried, heated to melting
temperature in a furnace in order to separate the iron from impurities (the slag), hammered to remove more impurities, and then forged into the de
sired shape.

Burning wood itself does not yield a temperature high enough for work-

ing with iron. Instead, the wood must first be burned to form charcoal,
which does sustain a sufficiently hot fire. Measurements in several countries
show that it takes on the average about four pounds of wood to make one
pound of charcoal. Because of that requirement, plus the low iron content
of bog iron, Viking iron extraction and tool production and even the repair
of iron tools consumed enormous quantities of wood, which became a lim
iting factor in the history of Viking Greenland, where trees were in short
supply.

As for the social system that Vikings brought overseas with them from the
Scandinavian mainland, it was hierarchical, with classes ranging at the lowest level from slaves captured in raids, through free men, up to chiefs. Large
unified kingdoms (as opposed to small local chiefdoms under chiefs who
might assume a title of "king") were just emerging in Scandinavia during
the Viking expansion, and overseas Viking settlers eventually had to deal
with kings of Norway and (later) of Denmark. However, the settlers had emigrated in part to escape the emerging power of would-be Norwegian
kings, so that neither Iceland nor Greenland societies ever developed kings
of their own. Instead, the power there remained in the hands of a military
aristocracy of chiefs. Only they could afford their own boat and a full set of
livestock, including the prized and hard-to-maintain cows as well as the less
esteemed low-maintenance sheep and goats. The chief's dependents, retainers, and supporters included slaves, free laborers, tenant farmers, and inde
pendent free farmers.

Chiefs constantly competed with one another both by peaceful means
and by war. The peaceful competition involved chiefs seeking to outdo each
other in giving gifts and holding feasts, so as to gain prestige, reward follow
ers, and attract allies. Chiefs accumulated the necessary wealth through trading, raiding, and the production of their own farms. But Viking society
was also a violent one, in which chiefs and their retainers fought each other
at home as well as fighting other peoples overseas. The losers in those internecine struggles were the ones who had the most to gain by trying their
luck overseas. For instance, in the
a.d. 980s,
when an Icelander named Erik
the Red was defeated and exiled, he explored Greenland and led a band of
followers to settle the best farm sites there.

Key decisions of Viking society were made by the chiefs, who were moti
vated to increase their own prestige, even in cases where that might conflict
with the good of the current society as a whole and of the next generation.