Complex sentence: By the end of the following year they had captured Cusco, the Inca capital, and executed emperor Atahualpa; in his place they crowned his half-brother Manco Inca, expecting to dominate the country with his help.
Split into simpler sentences: By the end of the following year they had executed emperor Atahualpa and captured the Cusco, the Inca capital. They crowned Manco Inca, a half-brother of Atahualpa, as the new emperor, expecting to rule the country with his help.