 Margaret's marriage in 1503 to James IV linked the royal houses of England and Scotland, which a century later resulted in the Union of the Crowns; though it was intended that her famous younger brother Henry VIII, would be the main royal line of descent it is actually Margaret's heirs that became the royal bloodline.Upon his ascent to the English throne, Margaret's great-grandson, James VI and I, was the first person to be monarch of both Scotland and England after Elizabeth I died childless.Margaret was baptised in St. Margaret's Church, Westminster.