 Complete the following phrase:  After his work in Germany, Tidbury was employed by the Foreign Office as part of the North Silesian Plebiscite Commission until 1922. He held various postings as a general staff officer between then and 1935 at the War Office and Egypt. Promoted to brevet lieutet colonel in July 1937, Tibury received the full rank on New Years Day 1936 and exactly seven months later became a colonel. In these capacities, he commanded the 1st Battalion, Middlesex Regiment. On 22 August 1938, he was promoted to the temporary rank of brigadier and given command of the 18th Infantry Brigade, then serving in Mandatory Palestine during the 