EDES, nationalist guerrilla force that, bolstered by British support, constituted the only serious challenge to EAM-ELAS control of the resistance movement in occupied Greece during World War II. Led by Gen. Napoleon Zervas, EDES was originally liberal and antimonarchist, but it moved steadily to the political right. It cooperated with ELAS for a time in operations against the Germans and Italians, but, between October 1943 and February 1944, the two guerrilla groups fought each other. The British hoped to build EDES into a force strong enough to rival EAM-ELAS, but it was incapable of extending its influence far beyond Epirus (Modern Greek: Íperos). During the fighting between ELAS and the British, which began in December 1944, the EDES army was destroyed by ELAS in four days.