A tiny drawing of a young lion by Rembrandt has sold for a record €12.7 million to an undisclosed buyer at Sotheby’s on Wednesday, with the proceeds going to wildlife charity Panthera.

The drawing, A Young Lion Resting, is thought to date from between 1638 and 1642 and is the only drawing by Rembrandt to come on the market in a century.

Purchased in 2005 by American billionaire and historian Thomas S Kaplan, it was the only remaining known drawing by Rembrandt to be part of a private collection. It went on show with other priceless 17th-century works from the Leiden Collection in Amsterdam last year.

There are 15 known animal drawings by Rembrandt, six of them of lions. The other five are scattered among museums in London, Paris, Amsterdam and Rotterdam.

According to experts, exotic animals were sometimes brought to the Netherlands from the colonies to be put on show at fairs. Two such fairs are known to have taken place at the Waterlooplein, near Rembrandt’s house and he may have seen the lions there.

Rembrandt also drew an Indian elephant brought to the Netherlands as a novelty.

Kaplan, who says wildlife conservation is one of his non-profit passions, will donate the money to Panthera, which fights to protect big cats and their habitats.