Many of the ways the world was organized began to shift between 1500 and 1775.

• To begin with, most portions of the world were brought into frequent, continuing communication in ways that had never happened before.

• Whereas there had previously been multiple "worlds" in the world—the Chinese world, the Indian Ocean world, the Mediterranean world, and the Americas, all of which were unknown to Europeans, Asians, or Africans—after 1500, two new ties united the whole planet for the first time.

Christopher Columbus' trip in 1492 opened up the New World and formed new links between the Americas, Europe, and Africa.

• The third important process is the development of a system of sovereign nations in Europe, as well as the relationship between that process and conflict.

In compared to Asian empires, European governments appear to be weak and frail creations incapable of competing with greater empires.

• Their kings were so impoverished that they had to regularly seek loans to keep their military operational.

• They were so little that they lacked the resources needed for self-defense, and had the Spanish succeeded in building an empire in Europe and eliminated interstate warfare, independent European governments would not have emerged at all.

• As it was, the system of European interstate fighting favored a specific type of state that emerged.

Fourth, these developments occurred during a seventeenth-century "Global Crisis," during which a global climatic event known as the "Little Ice Age" interacted with wars and civil wars to reduce human populations around the world and influence how rulers and their subjects viewed the purpose of states and political order.

• The Little Ice Age, driven by many natural phenomena that lowered the quantity of solar radiation reaching the Earth's surface, most likely began in the fourteenth century and may have continued until the early nineteenth century.

The human crises of the seventeenth century lasted considerably shorter, but were probably exacerbated by the negative impacts of a cooling environment on harvests and the tax revenues rulers of the time received.

After 1500, five empires grew substantially throughout Eurasia, redefining the continent's political demarcations and effectively eliminating the function of nomadic warriors:

• China in the east

• Russia in the center

• Mughal India in the south

• Safavid Iran in the southwest

• Ottoman empire in the west.

Although they did not all expand at the same time or rate, and one or more suffered substantial losses, the expansion push of these empires was so enormous that by 1775, virtually all of Eurasia—except for the European far west—was under the dominion of one or more of these empires.

Russia and China were the two most dramatic examples of empire growth, with the former more than quadrupling its size from 1500 to 1800 and the latter more than doubling its size.

• The Russian empire grew out of the principality of Moscow, which was nothing more than a stockade (called a "kremlin") surrounded by a few thousand square kilometers of woodland mixed with farms around 1300.

• Muscovite kings extended their territory during the following 150 years by conquering neighboring Russian-speaking states.

• The Muscovite king Ivan IV ("the Terrible," r. 1533-1584) stretched his dominion east to the Ural Mountains, north to the Barents Sea, and south to the Caspian Sea throughout the 1500s.

Following a "troubled period" during the global financial crisis.

• The nascent Qing dynasty quickly embarked on a series of military expeditions, particularly under the command of Emperor Qianlong (r. 1736–1795).

• The Qianlong emperor battled in the northwest and west, conquering various non-Chinese peoples, most notably the Muslim Uigurs and Tibetans, and absorbing them and their territory into the empire.

• By the time he was completed in the 1770s, the Chinese empire had more than quadrupled in size with the addition of Tibetan, Mongol, and other peoples, despite the fact that the new lands were thinly inhabited steppe, semidesert, or hilly regions.