Faisal's reign grew increasingly unstable against a backdrop of economic inequality coupled with the rise of Communism, anti-imperialist sentiment and mounting Pan-Arab nationalism. The overthrow of the Egyptian monarchy in 1952 and the formation of the United Arab Republic in February 1958 only provided further impetuses to revolution. The Hashemite Arab Federation was formed between Iraq and Jordan in February 1958 with Faisal as its head, which did not quell widespread opposition. In July 1958, a group of Royal Iraqi Army officers led by Abd al-Karim Qasim mounted a coup d'état and overthrew the monarchy. Faisal was executed along with numerous members of his family in the process.