On February 14, 1958, the Hashemite Kingdoms of Jordan and Iraq announced the formation of the Arab Federation, a political union between the two cousin-monarchs, King Hussein and King Faisal II, intended as a counterweight to the Egyptian-Syrian union declared days earlier under Gamal Abdel Nasser. The federation dissolved just six months later, in July 1958, when a military coup in Baghdad violently overthrew and killed Faisal II and much of the Iraqi royal family.
The Arab Federation was announced with considerable pageantry, framed as a natural union of two monarchies descended from the Hashemite dynasty, tracing lineage to the Prophet Muhammad. It was widely understood as a defensive maneuver: days earlier, Nasser's Egypt and Syria had merged into the United Arab Republic, a pan-Arabist union that threatened to isolate the more conservative, Western-aligned Hashemite kingdoms.
The union never had time to develop real institutional weight. On July 14, 1958, Iraqi army officers led by Abd al-Karim Qasim stormed the royal palace in Baghdad in a bloody coup; King Faisal II, only 23 years old, was shot along with most of his family, and the federation collapsed instantly. Jordan's King Hussein narrowly survived the political fallout and went on to rule for over four decades, while Iraq spiraled into a series of coups that eventually paved the way for Ba'athist rule and, decades later, Saddam Hussein.