Our Icelandic grandfather, Einar Jon Magnusson was born Einar Jonsson as the custom is to accept your father's first name plus son or dottir as your surname.
When my grandfather came to Canada if was to work as a fisherman on Lake Winnipeg with his uncle Magnus Magnusson.
Prior to his marriage in 1916, our grandfather changed his surname to Einar Jon Magnusson to honour his Uncle who had provided him with a home with their family, and work with the company.