After completing his studies at the
Royal Military College, Sandhurst, Bastyan was
commissioned as a
second lieutenant into the
British Army's
Sherwood Foresters on 30 August 1923, and promoted to
lieutenant on 30 August 1925. He was promoted to
captain in the
West Yorkshire Regiment on 4 April 1935 and attended the
Staff College, Camberley from 1936 to 1937, transferring to the
Royal Irish Fusiliers in 1937, and seeing service in
Palestine from 1938 to 1939. Bastyan was promoted to
major on 30 August 1940. From November 1939 to June 1941, during the
Second World War, Bastyan served as a
GSO II in Palestine with the
Royal Irish Fusiliers He served as assistant quarter-master general in the
Middle East from July 1941 to May 1942, subsequently as deputy director of the Higher Commander's Course from May to October of that year. by which time he was a temporary
lieutenant colonel. He was promoted to temporary
brigadier the following month and confirmed as a war substantive lieutenant colonel in November 1942. Bastyan served as a temporary brigadier (quartermaster) from then until January 1944, when he was appointed a
Commander of the Order of the British Empire. He was appointed a
Companion of the Order of the Bath in August 1944. In December 1944, Bastyan was appointed an acting
major general (Administration, Allied Land Forces, South East Asia). He was promoted to the permanent rank of
colonel in July 1945, He was promoted to substantive major-general on 26 January 1948, with seniority from 13 April 1946. After the war, Bastyan, after serving as an instructor at the
Imperial Defence College, became Chief of Staff at
British Army of the Rhine in October 1946 (which involved looking after the
logistics for the
Berlin airlift between 1946 and 1948). He went on to be Chief of Staff at
Eastern Command in July 1949, Director of Staff Duties at the
War Office in November 1950 and General Officer Commanding
53rd (Welsh) Infantry Division in October 1952. ==Vice-Regal career==