The word “robot” was first used in 1920; but when Science Museum curator Ben Russell started to research the history of humanoid machines for the current blockbuster exhibition, he discovered something he was not expecting. The first creator of these objects, he found, was the Catholic Church. The year was around 1560; the place, a monastery – probably in Spain.

The first robot stands a foot or so high, and is driven by a key-wound spring. It is a robotic monk: it walks around, strikes its chest with its right arm, raises and lowers a wooden cross and holds a rosary. It nods its head, rolls its eyes, and mouths silent prayers. And perhaps most extraordinary of all, 450-plus years on, it remains in working order.

The mechanical monk is one of the first exhibits in a show (to 3 September) that aims to explore the human obsession to recreate ourselves. “What we wanted to do,” explains Russell, “was ask: ‘why do we do this?’ ‘Why’ is a much more interesting question than ‘how’. Why would you create a machine that’s lifelike?”

The robotic monk was manufactured as a kind of mechanical ex-voto for King Philip II, whose son had been injured by a horse and was close to death. Philip, it was said, made a bargain with God. If his son survived, he would get the best clockmaker in the business to construct a lifelike model of a praying monk, which would wow the masses. And wow them it undoubtedly would have done, when the son duly recovered and the model was subsequently made.