Martha is the sister of Mary Magdalen and Lazarus. Christ often visited their home and, on one such occasion, Martha complained to him that her sister was listening to his words rather than tending to her chores. Christ retorted that it was Mary who had chosen "the better part." This is the scene Diego Velázquez depicted in his Christ in the House of Mary and Martha (c. 1620) at the London National Gallery. With this episode Martha came to symbolize the active Christian way of life and her sister Mary the contemplative existence. Martha is usually included in scenes of the Raising of Lazarus, as in Giotto's rendition in the Arena Chapel, Padua, of 1305 and Caravaggio's of 1609 (Messina, Museo Nazionale). In fact, she is the one who called on Christ after her brother's death to bring him back to life. Martha and her siblings went to France after Christ's death. There in the woods between Arles and Avignon, a dragon threatened the inhabitants of the region. Martha found the creature in the woods hurting a male youth. She doused the dragon with the holy water she carried in an aspersorium (vessel used to contain holy water) and held her cross in front of it. The dragon was appeased and allowed St. Martha to bind it with her girdle. Francesco Mochi's St. Martha in the Barberini Chapel at Sant' Andrea della Valle, Rome (1609-1628), shows her bending down to place the aspersorium in the monster's mouth.
Historical dictionary of Renaissance art. Lilian H. Zirpolo. 2008.