The Battle of Cos was fought in c. 261 BC, or as late as 255 BC, between an Antigonid fleet and a Ptolemaic fleet. Antigonus II Gonatas led his forces to victory, possibly over Patroclus, admiral of Ptolemy II. It has been widely assumed that the battle severely damaged Ptolemaic control of the Aegean, but this has been contested[1] After the battle, Antigonus dedicated his flagship to Apollo.