Complex sentence: The term "United Armenia" was created during the Armenian national awakening in the second half of the 19th century, when the Armenian-populated areas were divided between the Russian Empire (Eastern Armenia) and the Ottoman Empire (Western Armenia).
Split into simpler sentences: The term "United Armenia" was created during the Armenian national awakening in the second half of the 19th century. During these period, the Armenian-populated areas were divided between the Russian Empire (Eastern Armenia) and the Ottoman Empire (Western Armenia).