During the Invasion of Poland, Żeligowski volunteered for the Polish Armed Forces, but was not accepted due to his old age (he was 74 at that time) and poor health. Nevertheless, he served as an advisor to the command of the Polish southern front. After the Polish defeat, he evaded being captured by the Germans and the Soviets and managed to reach France, where he joined the Polish Government in Exile headed by General Władysław Sikorski. An active member of the "Polish National Council", an advisory body, he escaped to London after the French defeat in 1940.