Career
He was one of the civilian Promoters of the Siamese Revolution of 1932 that changed the country"s form of government from absolute to constitutional monarchy. He was closely associated with Pridi Banomyong. In the government of Field Marshal Plaek Phibunsongkhram he served as Minister of Foreign Affairs, but resigned when Phibunsongkhram led Thailand into World World War II alongside Japan.
After the end of war, he served as Minister of Justice, Finance, Foreign Affairs and Deputy Prime Minister in several short-lived cabinets.
From 1949 to 1952 he was the first dean of the Faculty of Political Science, Thammasat University. Direk served in many important posts in the Thai government during the early years of constitutional rule.
During World World War II, he held the post of Foreign Minister to become the Ambassador to Japan. He also held the posts of Deputy Prime Minister, Foreign Minister (multiple times), Justice Minister, and Finance Minister.
He also served as the Thai Ambassador to the Court of Saint James"s (England), Germany and Finland.
Direk also founded the Thammasat University Faculty of Political Science. Direk"s younger brother was Pairote Jayanama, former Permanent Secretary of Foreign Affairs (who had 4 sons who eventually became ambassadors), and Department of Administration and Management Jayanama, an Air Force General at the time. One son, Wattana Jayanama, became an important figure during the establishment phase of the Bank of Thailand.