The articles on these historical figures are from Wikipedia, and they are reasonably sound. I have put these here to help let you grasp the connections between the figures, but it is to be borne in mind that Shakespeare's narrative is far from the historical truth in a number of places.
Edward, Prince of Wales, [afterwards King Edward V], son to King Edward IV
George, Duke of Clarence, brother to the King
Richard, Duke of Gloucester, [afterwards King Richard III], brother to the King
Elizabeth Woodville, Queen to King Edward IV
Margaret, widow of King Henry VI
Duchess of York, mother to King Edward IV
Lady Anne, widow of Edward Prince of Wales (son to King Henry VI) [afterwards married to Richard]
Richard, Duke of York, son to King Edward IV
Henry, Earl of Richmond, [afterwards King Henry VII]
Thomas Bourchier, Archbishop of Canterbury
Thomas Rotherham, Archbishop of York
John Morton, Bishop of Ely
Henry Stafford, Duke of Buckingham
Thomas Howard, Duke of Norfolk
Earl of Surrey, Son of the Duke of Norfolk
Anthony Woodville, Second Earl Rivers, brother to Elizabeth
Thomas Grey, Marquess of Dorset, son to Queen Elizabeth
Lord Grey, son to Queen Elizabeth
Lord Stanley, called also Earl of Derby, husband of Margaret Beaufort, father of Henry, Earl of Richmond, later Henry VII
Sir Robert Brakenbury, Lieutenant of the Tower
Christopher Urswick, a priest
Lord Mayor of London. Sheriff of Wiltshire
Sir Walter Herbert
Second Priest
Tressel, gentleman attending on the Lady Anne
Berkeley, gentleman attending on the Lady Anne
A young son of Clarence
A young Daughter of Clarence
Ghosts of those murdered by Richard III, Lords and other Attendants; a Pursuivant, Scrivener, Citizens, Murderers, Messengers, Soldiers, &c.
© Copyright 2015, Bruce A. McMenomy