Complex sentence: On April 24,1821, Kehayabey Mustafa set out with a force of 4,000 men to capture the main Greek camp at Valtetsi which was defended by a small Greek force under the Maniot leader Kyriakoulis Mavromichalis.
Split into simpler sentences: On April 24,1821, Kehayabey Mustafa set out with a force of 4,000 men to capture the main Greek camp at Valtetsi. The camp was defended by a small Greek force under the Maniot leader Kyriakoulis Mavromichalis.