For over a year Gilliard was in the service of General Maurice Janin, the commander of the French military mission during the Russian Civil War, until early November 1919 when along with thousands of others, including ministers and government officials of the old regime, he fled Omsk and headed east on the Trans-Siberian railway. After a journey lasting six months, he arrived in Vladivostok in early April 1920. He then took an American ship to San Francisco, and from there travelled by ship along the Pacific coast, through the Panama Canal, across the Atlantic Ocean and Mediterranean Sea to Trieste. He travelled through Italy to Switzerland, and in August 1920 he reached his parents' home in Fiez, which he had left 16 years before.