Throughout its nearly 1,000-year history as a royal palace, fortress, prison, and treasury, the Tower of London has hosted countless members of royalty. Estimates suggest well over 100 individual royals—from reigning monarchs and consorts to princes, princesses, and foreign dignitaries—have resided in or visited the Tower. Notable stays include Elizabeth I (as a prisoner), the Princes in the Tower, and numerous coronation preparations. Today, it remains a working royal palace (the Crown Jewels are kept there) and a UNESCO World Heritage Site.