The seventeenth and eighteenth centuries witnessed the development of a Mongol identity. The Mongol conquests in the thirteenth century had laid the foundations but had not truly forged such an identity. These earlier events provided, in modern parlance, the cultural memory that eventually served to unify them. However, the Mongol Empire actually revealed the fractiousness of the Mongols and their inability to promote the unity that might gradually have fostered a Mongol identity. As Joseph Fletcher argued, the creation of a supra-tribal identity for nomadic herders has proven to be extremely difficult. The so-called Mongol Empire attested to this predicament, as within two generations it evolved into four separate Khanates, which occasionally waged war against each other. For example, individual Khanates frequently sided with non-Mongols against fellow Mongols. In addition, the military, the quintessential Mongol institution, was not, as the Empire expanded, composed simply of Mongols. Turks, Persians, and even Chinese served in and sometimes led the Mongol armies, contributing to the blurring of Mongol identity.