Sinai Peninsula.
During the war of 1967, Israel took control of the Sinai Peninsula. It was returned to Egypt under the terms of the 1979 Peace Treaty.
Egypt and Israel are not good allies as such, may be technically because Egypt is well aware that Israel is there to stay, but they do recognize each other after the signing of the Israel-Egypt Peace Treaty in 1979.
Israel signed a peace treaty with Egypt in 1979 and with Jordan in 1994.
March, 1979
Leader of Egypt, Anwar el-Sadat and Israeli Prime Minister Menachemsignedthe treaty.(?)
Because President Anwar Sadat of Egypt agreed to a peace treaty with Israel and part of that peace treaty was for Egypt to get their land back (Sinai Peninsula).
Egypt of course
Egypt in 1979 and Jordan in 1994.
Israel.
Egypt and Israel signed a mutual peace treaty in 1978. Whether or not the provision was explicitly stated in the text of the treaty, you don't sign and ratify a formal treaty with a country whose existence you don't acknowledge.
Egypt
It was called the Camp David Accords of 1979. The basic terms of the treaty were that Israel would withdraw from the Sinai Peninsula in phases until 1982 and return it to Egypt. Egypt, in turn, would recognize the State of Israel and maintain the Sinai Peninsula as a demilitarized zone.