Japanese news photo June 1, 1943
Sugiyama (left on first row), as minister of War in Kuniaki Koiso's (third from left on front row) cabinet, with Mitsumasa Yonai (right on front row)
After graduating from the 22nd class of the Army Staff College in 1910 and serving on the Imperial Japanese Army General Staff, Sugiyama was posted as military attaché to the Philippines and Singapore in 1912.
Promoted to major in 1913, he was posted again as military attaché to British India in 1915. During this time, he also visited Germany, and became acquainted with the use of aircraft in combat in World War I.
On his return, Sugiyama was promoted to lieutenant colonel, and commander of the 2nd Air Battalion in December 1918. He was a strong proponent of military aviation, and after his promotion to colonel in 1921, became the first head of the Imperial Japanese Army Air Service in 1922.
In May 1925, Sugiyama became a major general and acting Vice War Minister in June 1930. In August, he became Vice War Minister and a lieutenant general. He returned to command the expanded Imperial Japanese Army Air Service in March 1933. Sugiyama was promoted to full general in November 1936.
He was War Minister in the Hayashi Cabinet (1937) and the Konoe Cabinet. During World War II, he was made a field marshal (1943) and commander-in-chief of the Mainland Defense Forces.
Although never elected to political office, Sugiyama is regarded as a nationalist politician. He started in the Tōseiha faction, led by Kazushige Ugaki, with Koiso Kuniaki, Yoshijirō Umezu, Tetsuzan Nagata, and Hideki Tōjō. They opposed the radical Kodaha faction under Sadao Araki. Later both factions combined in the Imperial Way Faction movement, and Sugiyama became one of its ideological leaders.