Garner was born in the front room of his grandmother's house in Congleton, Cheshire, on 17 October 1934. He was raised in nearby Alderley Edge, a well-to-do village that had effectively become a suburb of Manchester. His "rural working-class family", had been connected to Alderley Edge since at least the sixteenth century, and could be traced back to the death of William Garner in 1592. Garner has stated that his family had passed on "a genuine oral tradition" involving folk tales about The Edge, which included a description of a king and his army of knights who slept under it, guarded by a wizard. In the mid-nineteenth century Alan's great-great grandfather Robert had carved the face of a bearded wizard onto the face of a cliff next to a well, known locally at that time as the Wizard's Well.