Complex sentence: After fortifying the town's harbour, he returned home a few years later and captained the "Unicorn" at the Battle of Lowestoft in 1665 and later the "Prince" at the Battle of Solebay in 1672.
Split into simpler sentences: After fortifying the town's harbour, he returned home shortly. Later he commanded the "Prince" at the Battle of Solebay in 1672.