What is referred to by 'canvasback'?

What is associated with: canute iv later the holy 1080 to 1086? Based on the clue 'canute reigned there in the 11th century', what is the answer? What is associated with: canute the great forced this countrys olaf into exile in 1028 put his own son on the throne? Based on the clue 'canvas housing for prisoners or a list of book cha...', what is the answer? Based on the clue 'canyonlands national park arches national park ar...', what is the answer? Based on the clue 'cap de la madeleine sept iles trois rivieres', what is the answer? Based on the clue 'cap gris nez which extends into this strait is fra...', what is the answer? Based on the clue 'capable of allowing fluids to pass through it', what is the answer?