Closure of the Suez Canal (1967–1975)
On 6 June 1967, after the start of the Six-Day War, Egypt closed the Suez Canal, which it owned and operated, and kept it closed until 5 June 1975, through most of the Israeli occupation of the Sinai Peninsula including the east bank of the Canal. The Six-Day War had begun the day before the closure on 5 June 1967 between Israel and several Arab states including Egypt.
Source: Wikipedia — Closure of the Suez Canal (1967–1975) (CC BY-SA 4.0)