Complex sentence: Later, he forced the Cypriot people to pay special taxes to assemble an army and siege machines, and he besieged Famagusta for three years but in vain, since there was access from the sea to the city.
Split into simpler sentences: Later, he forced the Cypriot people to pay special taxes to assemble an army and machines for siege and he besieged Famagusta. The siege lasted for three years but it proved useless since there was access from the sea to the city.