Until the mid 1800’s the top of the head was standard. When women started wearing extravagent hats to Church and complained about the ashes that where sprinkled on them the ashes where moved to the forehead. Up until the Second Vatican Council it was still the custom to sprinkle ashes on the heads of clerics, (The first step to the priesthood was to become a tonsured cleric, in monastic communities the head was shaved leaving only a ring of hair around the head. In Europe, a silver dollar sized area on the back of the head was shaved to indicate clerical status. The ashes where sprinkled there. After Pope Paul VI supressed Tonsure, the Minor Orders and the Sub Deaconate in the Latin Rite, the custom was for the most part dropped.