The mathematician and experimental philosopher Galileo Galilei was held under house-arrest for the last 10 years of his life, owing to his independent and uncooperative attitude to Church orthodoxy on the question of heliocentrism, i.e. whether the sun was the centre around which the earth revolved or vice versa. The English poet John Milton visited him at this time, in Galileo's house at Arcetri near Florence: in Milton's words, 'There it was that I found and visited the famous Galileo grown old a prisoner to the Inquisition, for thinking in Astronomy otherwise than the Franciscan and Dominican licensers thought'. Several aspects of this episode made it attractive to later writers and painters. There is the contrast between the youth of Milton and the age of Galileo, the encounter of Europeans from north and south of the Alps, and the meeting of a poet and a philosopher.