This is the altar piece of the Oratory and was commissioned by Grand Master Alof de Wignacourt. It is the largest painting produced by the artist and the only one known to be signed.
The Beheading of St John the Baptist was completed in 1608 and depicts the saint at the moment of his martyrdom. The executioner holds down his head whilst the janitor instructs him to finish the job. An old lady clasps her head in horror whilst the young woman, possibly Salome, holds a large charger to receive the head. Caravaggio's name is scrawled in the blood oozing out of St John’s neck.
The painting measures 361cm x 520cm.