Milligan and Harry Secombe became friends while serving in the Royal Artillery during the Second World War. Famously, Milligan first encountered Secombe after Gunner Milligan's artillery unit accidentally allowed a large howitzer to roll off a cliff, under which Secombe was sitting in a small wireless truck: "Suddenly there was a terrible noise as some monstrous object fell from the sky quite close to us. There was considerable confusion, and in the middle of it all the flap of the truck was pushed open and a young, helmeted idiot asked 'Anybody see a gun?' It was Milligan." Secombe's answer to that question was "What colour was it?" Milligan met Peter Sellers after the war at the Hackney Empire, where Secombe was performing, and the three became close friends.:20