Marwick's father was a travelling salesman who had a smallholding in the parish of Evie, to the north of Mainland, Orkney.
Diagnosed with scoliosis in 1925 when he was ten years old, Marwick could no longer attend school as his days had to be spent lying on a wooden board.
[1] After Marwick's marriage his home provided a meeting-place for local intellectuals, including George Mackay Brown and Robert Rendall.
[4] Other media work undertaken by Marwick included broadcasting on local and Scottish national radio programmes.
[6] He died in July 1977, having swerved off a straight road and crashed into a farm steading when driving.