The occupation of the Gaza Strip by the United Arab Republic began in 1959 following the dissolution of the All-Palestine Protectorate, which had ruled the Gaza Strip as a client state of Egypt since the 1948 Arab–Israeli War, and its merger with the United Arab Republic.
The 1949 Armistice Agreements, which ended the Arab–Israeli War by delineating the Green Line as the armistice line between Israel and its four neighboring countries (Lebanon, Syria, Jordan, and Egypt), left the Kingdom of Egypt in control of a small swath of territory that was part of Mandatory Palestine prior to the war. That swath of territory became known as the Gaza Strip. In 1949 Egypt created the client state named the All-Palestine Government which lasted until 1959, the year after the Republic of Egypt and the Second Syrian Republic merged to form a single sovereign state known as the United Arab Republic. The Egyptian occupation of the Gaza Strip was interrupted for 4 months in late 1956 and early 1957 when Israel briefly occupied the strip as part of the 1956 Suez Crisis. The Egyptian occupation ended entirely during the 1967 Six-Day War, after which the territory became occupied by Israel with the establishment of the Israeli Military Governorate.