The Merkava series of tanks dates to the 1960s, when Israel drew up plans to remove its military-industrial complex from reliance on foreign factories. Israel's economy and national reserves, backed by U.S. military grant aid, allowed it to purchase nearly any land, sea, or air platform and weapon from friendly nations, but Israel's infrastructure was not capable of producing those items domestically.
In 1965, Israel's military establishment began research and development on a domestically-produced tank, the "Sabra" (Hebrew slang for a Jew born in Israel (not to be confused with the modern Sabra tank). Initially, Britain and Israel collaborated to develop the United Kingdom's Chieftain tank that had entered British Army service in 1966. However, in 1969, Britain decided not to sell the tank to Israel for political reasons.
Israel Tal, who was serving as a brigade commander after the Suez Crisis, restarted plans to produce an Israeli-made tank, drawing on lessons from the 1973 Yom Kippur War, in which Israeli forces were outnumbered by those of the Middle East's Arab nations. Realizing that they could not win wars of attrition, the Israelis set stringent requirements of crew survivability and safety for the new tank platform.
By 1974, initial designs were completed and prototypes were built. After a brief set of trials, work began to retool the Tel HaShomer ordnance depot for full-time development and construction. After the new facilities were completed, the Merkava was announced to the public in the International Defense Review periodical. The first official images of the tank were then released to the American periodical Armed Forces Journal on May 14, 1977. The IDF did not officially adopt the tank until December 1978, when the first full battalion of 30 tanks was delivered for initial unit training.
A Merkava prototype with a Patton "Magach" turret
A prototype with a Centurion "Shot Kal" turret