Sebastian was a Roman centurion, who was discovered to be a Christian and was sentenced to death by Emperor Diocletian. He was bound to a stake and shot with arrows. He was left for dead, although the arrows had not killed him and he was eventually stoned to death. The story is taken from the 'Golden Legend'.
Honthorst was one of the first artists to portray Saint Sebastian as a half-length figure, slumped forward in a seated position. The pose was subsequently adopted by other followers of Caravaggio in Utrecht, including Jan van Bijlert and Hendrik ter Brugghen in the mid-1620s. This picture was probably painted shortly after Honthorst's return to Utrecht in 1620.