This book became the first attempt of theory by a professional historian and at the same time the first IR research extensively based on primary sources. Both works found that most civilizations most of time were unipolar and the European long balance of power was exceptional in world history. Victoria Tin-bor Hui and Ostrovsky explained it by the expanding nature of the European system, while hegemonic stability needs a geopolitically closed system. The next complication, however, was the kind of unipolarity. Most of unipolar civilizations were universal empires rather than system-wide hegemonies. The former are distinct by formal rule, territorial conquest and annexation, and regular taxation. The team of Wohlforth disregarded this complication. Ostrovsky found in world history three system-wide hegemonies—Sumer, Qin in 364-221 BC and Rome in 189-63 BC. Three known cases The first striking element is that system-wide hegemonies were rare occasions in world history. The second striking element is that all three known hegemonies were anything but stable. Ostrovsky tested the HST on the three known cases: The hegemon of Sumer, House of Kish, sent envoys to Gilgamesh. Gilgamesh addressed the assembly of warriors: "Let us not submit to the House of Kish, let us smite it with weapons!" The assembly wholeheartedly agreed. "At the word of the fighting men of his city his heart rejoiced, his spirit brightened." A battle was fought and the hegemon was defeated and imprisoned. Hegemony is as old as history. According to the Sumerian King List, Kish established the hegemony yet before the Flood. The anti-hegemonic resistance dates to the same dawn of history too, recorded in one of the earliest literary legacies of mankind. The hegemonic Qin did not produce anymore stability. The Warring States went more warring. Qin emerged victorious and hegemonic after a war in 364 BC. Shortly, almost all the rest of the Chinese world united into an anti-hegemonic alliance, called Vertical or Perpendicular, and at least once the whole Chinese world "united their wills and joined their forces to attack Qin." "With a force of 1,000,000 soldiers drown from area ten times large than Qin, they beat upon the Pass [to the land of Qin] and pressed forward toward Qin." The same dreadful scenario repeated itself several times. Massive anti-hegemonic alliances characterized the period. As in Sumer, in the Warring-States China hegemony was bound with anti-hegemony. The Qin armies repeatedly crashed the anti-hegemonic alliances in at