Complex sentence: An attempt by the Turks to blockade the Berezan Island, and thus deny the Cossacks access to the sea, was defeated in the spring of 1616, the raiders going on to capture Kaffa, which was burned down after all of the slaves were freed.
Split into simpler sentences: An attempt by the Turks to blockade the Berezan Island, and deny Cossacks access to the sea, was defeated in the spring of 1616. The raiders went on to capture Kaffa, which was burned down after all the slaves were freed.