Back in the late 1980s plans were made to develop a successor to the British Army's Challenger battle tank.
Imaginatively called the Challenger 2 £90 million was invested in the prototype with the MoD subsequently ordering a total of 408 of the vehicles, at around £4 million a pop.
In 1994 the first tanks were delivered to the British Army and entered service 4 years later. While the last Challenger 2 rumbled off the production line in 2002 they're expected to remain in use until 2035.
Having already seen action in Bosnia, Kosovo and Iraq, to date the only time the tank has ever been seriously damaged during operations, was by another Challenger 2 in a friendly fire incident.