Answer:
On July 26, 1956, Egyptian President Gamal Abdel Nasser decided to nationalize the canal in order to facilitate the financing of the construction of the Aswan dam and, in response to the refusal of the United States and the United Kingdom to finance the work. The measure was greeted with outrage by France and the United Kingdom, the main shareholders of the Suez Canal, and maximum beneficiaries of the oil that circulated through it. On October 29 of that same year, the Sinai War began for those reasons. Egypt, in retaliation, sank forty ships in the canal, causing total blockade.
At the beginning of 1957, after the intervention of the UN, the withdrawal of the European powers and Israel was completed. The channel was reopened in the same year.
Since then, it was administered by Nasser until a new blockade in 1967, due to hostilities between Egypt and Israel in the Six Day War. The closure occurred, as in 1956, due to the blockade caused by the sinking of several ships inside the canal. It was reopened to international traffic in June 1975.