Editing Leopard 1 (section)

=== Gilded Leopard, ''Eber'' and ''Keiler'' ===
Almost as soon as the Leopard was introduced into service in 1965, Porsche was awarded a contract to study further improvements to the existing design, while awaiting deliveries of the MBT-70 in the mid-1970s. This original ''Gilded Leopard'' (''vergoldeter Leopard'') program expired in 1967 with no production order. In 1967, it had already become obvious that the MBT-70 would be a failure. The agreement between the US and the Federal Republic of Germany forbade any national development of an MBT apart from technological experimentation, so a new tank project was begun under the designation of ''Experimentalentwicklung'' or "experimental development", two prototypes of which were built.

When the MBT-70 program was ended, a further contract was offered under the name ''Boar'' (''Eber''), with an emphasis on using as many technologies from the MBT-70 as possible, but without the problematic XM150 152&nbsp;mm (6.0&nbsp;in) combined gun/[[MGM-51 Shillelagh]] missile launcher.  Two prototype vehicles were constructed using a new chassis from Porsche with the road wheels from the MBT-70 and the original Leopard engine. This was combined with a new Wegmann turret, mounting the MBT-70's [[Rheinmetall 120&nbsp;mm Gun|Rheinmetall 120&nbsp;mm smoothbore gun]]. Some also mounted the original 105&nbsp;mm L7.

These were considered promising enough that seven more were ordered, this time powered by the MTU engine designed for the MBT-70. When this happened, the ''Experimentalentwicklung'' team went public with their alternative design which they called the ''Keiler'' (a synonym of ''Eber''). In 1971, the minister of defence, [[Helmut Schmidt]], decided to abandon the ''Eber''-project and build 17 prototypes of a Leopard 2, based on the ''Keiler'' design, which had a turret with spaced [[sloped armour]]. The maximum weight was to be 50 tonnes.

During the 1973 [[Yom Kippur War]], 1950s and 1960s generation tanks were badly beaten by [[wire-guided missile]]s,{{citation needed|date=February 2023}} and it was realized that dramatically improved armour protection was needed. The decision was made to allow the tank to increase its weight to the next classification, Military Loading Class 60 (tonnes). A new design effort was started, with the spaced armour replaced with a much denser perforated armour assemblage. The new design would go on to augment and, after the [[Cold War]], sometimes replace the Leopard in many countries' armies.{{Citation needed|date=May 2022}}