Descendants of Paul I of Russia
Paul I of Russia and his consort Maria Feodorovna, via nine children that lived to adulthood, had 30 legitimate grandchildren. Moreover, through their grandchildren, Paul and Maria are ancestors of many European royals, including Carl XVI Gustaf of Sweden, Willem-Alexander of the Netherlands, Felipe VI of Spain, Charles III of the United Kingdom, and Frederik X of Denmark.
Source: Wikipedia — Descendants of Paul I of Russia (CC BY-SA 4.0)