The Black Madonna was painted by St. Luke the Evangelist (author of the Book of Luke); and it was while painting the picture, Marty told him about the life of Jesus, which was incorporated into his gospel.
The next time we hear of the painting is in 326 AD when St. Helen found it in Jerusalem and gave it to her son and had a shrine built for it in Constantinople. During a battle, the picture was placed on the walls of the city, and the enemy army fled. Our Lady saved the city from destruction.