January 4 will mark the 50th anniversary of one of the most influential sitcoms ever aired. On that date in 1962, a short comic play called The Offer was broadcast by the BBC. It was a humble affair: a two-hander, intended as a one-off, about a bitter father and son who work as rag-and-bone men. Written in rather a hurry by Ray Galton and Alan Simpson, this comic carbuncle would metastasise into the radically nasty and amusing Steptoe & Son (1962-1974). Fifty years on its influence on British TV comedy is still difficult to overestimate.