Israel responds to a build-up of Arab forces along its borders by launching a preemptive aerial attack against Egypt. Jordan subsequently entered the fray, but the Arab coalition was no match for Israel’s armed forces. In six days of fighting, Israel occupied the Gaza Strip and the Sinai Peninsula of Egypt, the Golan Heights of Syria and the West Bank and Arab sector of East Jerusalem, both previously under Jordanian rule. By the time the United Nations cease-fire took effect on June 11, Israel had more than doubled its size, including claiming the Old City of Jerusalem from Jordan.