By late 1663 and early 1664, the coalition had not only taken back Ottoman-conquered land but also cut off Ottoman supply lines and captured several Ottoman-held fortresses within Hungary. In the meantime, a large Ottoman army, led by the Grand Vizier Köprülü Fazıl Ahmed Pasha and numbering up to 100,000 men, was moving from Constantinople to the northwest. In June 1664, it attacked Novi Zrin Castle in Međimurje County (northern Croatia) and conquered it after one-month-long siege. However, on August 1, 1664, the combined Christian armies of Germany, France, Hungary and the Habsburgs won a decisive victory against the Ottomans in the Battle of Saint Gotthard.