The images are believed to be the oldest European depiction of the bird, trumping a similar discovery in a 15th-century artwork, and have sparked a reassessment of trading routes that existed more than 700 years ago.

The drawings are likely to be of a sulphur-crested cockatoo, a yellow-crested cockatoo or a Triton cockatoo, from the northern tip of Australia, New Guinea, or the islands around New Guinea, and show how trade in the waters around Australia’s north was flourishing in medieval times.

The sketches were discovered by Finnish researchers in the manuscript De Arte Venandi cum Avibus (The Art of Hunting with Birds), which was written in Latin by Frederick II, between 1241 and 1248, and is held in the Vatican library.