As the story goes, while prepping Jesus for burial, Joseph of Arimathea preserved the blood washed from the Lord’s lifeless body. During the Second Crusade (1150), Derrick of Alsace saved Jerusalem from the Muslims and was rewarded with the vial. He carted it home and presented it to Bruges’ Bishop (the scene portrayed in this mural). The dried blood suddenly turned to liquid, a miracle that continued to occur every Friday for the next 200 years.