In this lecture, I discuss the rise and decline of single party regimes in the Arab World from the 1950s to the 1960s. This includes Egypt, Tunisia, Algeria, Syria, Iraq, Libya, North Yemen and South Yemen. These regimes are known as the Arab Republics. Most of these regimes, except Tunisia, formed in the aftermath of military coups that overthrown Western backed governments. Military officers subsequently created single party states with socialist economies. They promoted Arab-Nationalism and the end of Western imperialism and Zionism in the region. They reached their height of power from the 1950s to the 1960s before declining in subsequent decades.