Complex sentence: During his reign, the Durrani Empire began to shrink, in an attempt to move away from disaffected Pashtun tribes he shifted the capital from Kandahar to Kabul and chose Peshawar as the winter capital in 1776.
Split into simpler sentences: During his reign, the Durrani Empire began to shrink. In an attempt to move away from disaffected Pashtun tribes, he shifted the capital from Kandahar to Kabul and chose Peshawar as the winter capital in 1776.