Ben Birchall - PA ImagesGetty Images The tank would end more than 100 years of all-British tanks. The British Army invented the tank in order to break the stalemate of World War I. The British Army’s next tank could be a joint effort with France and Germany. The U.K. is in discussions to replace the current Challenger II main battle tank (seen above) with a joint tank designed to replace French and German tanks in the mid-2030s. All three countries would fund and field the notional tank, dubbed “Eurotank.” British Army Mark I tank in action, World War I, 1918.