What lands were added to the russian empire under ivan iv, peter the great, and catherine the great?

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).

where are the options?

explanation:

profound political, administrative, and social changes in the british isles.