This paper deals with an unpublished 1406 archival source that may reveal the identity of an early 15th-century master mainly active in the Abruzzo region: the 'Maestro della cappella Caldora' ('Master of the Caldora Chapel'). His activity and the chronology of his œuvre, dating from the first to the third decade of the Quattrocento, are illustrated here and a small panel depicting the 'Mourning over the Dead Christ' is added to his limited catalogue. The painter Paolo dall'Aquila, documented in Subiaco in 1406, is thus proposed as the 'Master of the Caldora Chapel'.