The title of Lord Protector was not an invention of Cromwell's, however. It had previously been used by princes or other nobles exercising a regency while the heir apparent was still a minor. Notable examples of this are Richard, Duke of Gloucester who was Lord Protector to the 'Princes in the Tower' and Edward Seymour, Duke of Somerset, who was Lord Protector to the young Edward VI. It has not been used for any regent since the Restoration and it's highly unlikely that the title will ever be revived in the future.
