The fall of Gallipoli was the siege and capture of the Gallipoli fortress and peninsula, by the Ottoman Turks, in March 1354. After suffering a half-century of defeats at the hands of the Ottomans, the Byzantine Empire had lost nearly all of its possessions in Anatolia, except Philadelphia. Access to the Aegean and Marmara seas meant that the Ottomans could now implement the conquest of the southern Balkans, and could advance further north into the Serbian Empire and Hungary.