In 306 BC Salamis was the most important Greek city on the island of Cyprus. The island was held by Ptolemy I, the ruler of Egypt, who was using it as a base in his wars against Antigonus Monophthalmus, who held most of the coast of Asia Minor and Syria. In 306 Antigonus sent his son Demetrius (soon to be known as “the besieger”) to capture the island. He landed in the north east of the island with an army of 15,000 infantry and 400 cavalry, and advanced towards Salamis.
The island was defended by Ptolemy’s brother Menelaos, who had a smaller force - 12,000 infantry and 800 cavalry concentrated at Salamis. Despite being outnumbered Menelaos advanced north from Salamis, fighting a battle with Demetrius five miles from the city. Demetrius was victorious, and forced Menelaos back into Salamis.
Armed with the helepolis and a full range of the most advanced siege engines then available, Demetrius was able to destroy part of the city walls, but the defenders were able to destroy a significant part of the siege train in a night attack, and Demetrius was repelled, at least for the moment.
The city eventually fell after the very visible failure of a relief expedition led by Ptolemy in person. His fleet was defeated in battle just south of the city (Battle of Salamis of Cyprus). The sixty ships trapped in Salamis had fought their way past a blockading force, but only in time to witness Ptolemy’s defeat and to sail back into the city.
With the defeat of the relief expedition it was clearly pointless to continue the siege. Menelaos surrendered, and was returned to Egypt. Cyprus was soon entirely in Demetrius’s hands, along with 16,000 Egyptian soldiers. In the aftermath of the victory at Salamis Antigonus adopted the royal title, and made Demetrius his co-monarch. The capture of Cyprus was followed by a failed expedition to Egypt, and then in 305-304 by the more famous Siege of Rhodes.