The Yom Kippur War, Ramadan War or October War, also known as the 1973 Arab-Israeli War and the Fourth Arab-Israeli War, was fought from October 6 to October 26, 1973, between Israel and a coalition of Arab states backing Egypt and Syria. The war began with a joint surprise attack on Yom Kippur, the holiest day in Judaism, which coincided with the Muslim holy month of Ramadan. Egypt and Syria respectively crossed cease-fire lines to enter the Israeli-held Sinai Peninsula and Golan Heights, which had been captured and occupied since the 1967 Six-Day War. The conflict had all the elements of a severe international crisis, and ended with a near-confrontation between the two nuclear superpowers, the United States and the Soviet Union, both of whom launched massive resupply efforts to their allies during the war.
The war began with a massive and successful Egyptian attack across the heavily-fortified Suez Canal during the first three days, after which they dug in, and the southern front settled into a stalemate. In the north, the Syrians simultaneously attacked the critical Golan Heights and initially achieved threatening gains, after which their momentum waned. Within a week, Israel repelled the Syrian attack and launched a four-day counter-offensive, driving deeper into Syria. To relieve this pressure, the Egyptians renewed their offensive, but decisively failed to advance; the Israelis then counterattacked at the seam between two Egyptian armies, crossed the Suez Canal, and advanced southward in over a week of heavy fighting. Israel encircled elements of Egypt's Third Army after an agreed United Nations ceasefire resolution. This initially prompted tension between the superpowers, but a ceasefire was imposed cooperatively on October 25 to end the war. By the end of the fighting, Israeli forces were 40 kilometers from Damascus and 101 kilometers from Cairo.