He first probably finished the siege of Pagasae, to deny the Athenians a landing place in Thessaly. Pagasae was not part of the Thessalian Confederation, and Philip therefore took it as his own, and garrisoned it. The fall of Pagasae now left Pherae totally isolated.
Philip likely concluded the siege on Pagasae to prevent Athenians from landing in Thessaly. Pagasae was outside the Thessalian Confederation, so Philip claimed it as his own and garrisoned it. The fall of Pagasae left Pherae entirely cut off.