Historians in the West acknowledge that the period from 1750 to 1850 is the first age of global imperialism, when Britain and France, after internally refreshing their military and economic power as a result of the scientific and industrial revolution, fought one another for world domination in many places, including the territories of the Ottoman Empire. On the other hand, this era, for the Ottoman historians, is recognized as the age of transformation, in particular a search for renewal in the military system, as the Imperial Engineering Schools and new fighting forces began to evolve with the defeats and economic crises that necessitated certain radical reorganization and dramatic changes in the Ottoman ancien régime. The challenges to the classical system of the Ottoman thesis of rule began around 1730 and ended with a new order in around 1830. In this era, while the Ottomans were busy transforming from the inside on the one hand, they also confronted the rock of British economic imperialism and the relentless pursuit of Russian and other European territorial ambitions along the northern frontier.