Lecture 33: Long Trends—Expansion and State Power
this way “tributes,” to contrast them with “gifts” (which are given freely)
and “pro¿ ts” (which are generated through exchanges in competitive
markets). The trick was to maximize resource extraction without exhausting
the capacity of peasants to keep paying.Roughly speaking, we can track increasing power by charting the increasing
size of states. Rein Taagepera has estimated changes in the areas controlled
by particular states. His calculations highlight four main eras in the expansion
of state power. The ¿ rst city-states covered tiny areas. Uruk covered about
2.5 square kilometers (a tiny fraction of 1 megameter), though its rulers
also controlled nearby villages. The ¿ rst Mesopotamian state to include
several city-states, that of Sargon of Akkad (2371–2316 B.C.E.), may
have controlled 0.6 megameters. In the 2nd millennium B.C.E., the largest
states—those of Egypt at its height and Shang China—controlled about 1
megameter of territory, and most controlled much less. So 1 megameter
seems to have been a rough upper limit for empires formed before the 1st
millennium B.C.E. The Persian Achaemenid Empire, founded by Cyrus II
in 560 B.C.E., marks a sudden increase in the size of large states. It covered
about 5.5 megameters. For the next 1,500 years, the largest states ranged
from about 4 megameters (the Roman Empire) to about 10 megameters (the
earliest Islamic empires). In the last 1,500 years, much bigger empires have
appeared, starting with the Mongol Empire, which brieÀ y controlled about
24 megameters. These estimates hide eras of collapse and decline, such
as the decline of Mesopotamian states early in the 2nd millennium through
ecological collapse. Nevertheless, with the bene¿ t of hindsight the long trend
toward increasing state power is unmistakable.How did states expand their power and reach? Rulers increased their
military authority partly by recruiting larger armies and equipping them with
increasingly sophisticated weapons, such as chariots and siege weapons.
Some of the more important innovations, particularly in cavalry warfare,
came from the pastoral nomads of the Eurasian steppes. Road building and
the establishment of courier or post-horse systems allowed rulers to send
armies, supplies, and messages over large distances. We have a wonderful
description by Herodotus of the Persian “Royal Road” built between 550 and
486 B.C.E. between southern Persia and modern Turkey. As bureaucracies
expanded, they became more effective at managing tax collection over large