AbstractOn the basis of existing data on the dimensions, shape, surficial geology, and glaciological structure of ice island ARLIS-II, used in combination with aerial photographs of northernmost Ellesmere Island taken in 1950 and 1959, the source of the ice island is positively identified as the Alfred Ernest Ice Shelf. The duration of the recent drift of ‘Hobson's Choice’ ice island from the vicinity of the Alfred Ernest Ice Shelf to northern Ellef Ringnes Island, used as a model for the duration of the drift of ARLIS-II between the same points, suggests ARLIS-II broke off the ice shelf in approximately 1955.