An exhibition of work by Flemish master Rubens has opened at the National Gallery in London.
The Centaur drawing led to Rubens painting Ecce Homo in 1610
Rubens: A Master in the Making, which traces the first 15 years of the artist's career, includes a drawing which is on display for the first time.
Centaur, which dates back to 1606, was the working drawing behind the baroque artist's celebrated painting Ecce Homo, and was discovered by accident in 2001.
The exhibition also includes Rubens' famous work Massacre of the Innocents.
The painting, which dates from 1610, was largely unknown for many years and was even attributed to another artist, Frans de Neve.
It will be the last time the masterpiece is displayed at the London gallery before it returns to a private collection in Canada. It fetched £49.5m at auction in 2002.
Born in Westphalia (now Germany) in 1577, Peter Paul Rubens was a diplomat, scholar, collector and intellectual.
During his long and prolific career he worked for every major European leader and excelled in all types of paintings, from mythological and religious scenes to portraits and landscapes.
Massacre of the Innocents went unrecognised for 200 years
The exhibition, which runs from 26 October to 15 January 2006, features 45 paintings and 30 drawings that span from 1599 to 1614.
It begins as Rubens left Antwerp at the age of 22 and embarked on a study trip, where he was inspired by antique statues and the art of Michelangelo, Raphael and Caravaggio.
The show ends with Samson and Delilah and the Massacre of the Innocents, which mark when Rubens returned to Antwerp after eight years in Italy and Spain.
Eight anatomical sketches will be shown together for the first time, along with the sculptures that inspired them at the exhibition.
Centaur - full title Centaur tormented by Cupid - which was found in a bin containing a discarded set of drawings in a museum in Cologne, will also be reunited with Ecce Homo for the first time.