Sir Quackly McDuck was born in Scotland in the year 1010. He later became the leader of The Clan McDuck. In 1057 King Macbeth I of Scotland offered him a small treasure chest in exchange for his support in the ongoing war for the throne.
Sir Quackly agreed and served the king during the war, but became obsessed with protecting the treasure, and accidentally trapped himself inside the walls with his treasure, where he subsequently died.
Sir Quackly became a legend among the McDucks, who claimed that his ghost protected the treasure and the castle. In the story "The Old Castle's Secret", the villain Diamond Dick disguises himself as Quackly's ghost to scare Scrooge McDuck away.
Sir Quackly's remains and the treasure chest were found by Scrooge McDuck in 1948 located in a tree near Whitegate