With the demise of the Black Hand in the Salonika Trial (1917), the White Hand steadily gained control of the young and ambitious Prince Alexander. Živkovic was made the head of the Palace Guard in 1921, and started amassing power. In 1929, King Alexander I, along with officers of the White Hand orchestrated a coup in attempt to control the growing nationalist tensions in the country (especially in Croatia) and the instability of the Parliament. Živković, now a general, was appointed Prime Minister. The autocracy was eased in 1931, when the King re-instated some constitutional rights after his reforms completely failed in their purpose, and Živković lost his position in 1932 after organizing numerous show trials against minority leaders, ultra-nationalist groups, and communists.