The House of Griffins or House of Pomerania (; ), also known as House of Greifen, was a dynasty of dukes ruling the Duchy of Pomerania from the 12th century until 1637. The name "Griffins" was used by the dynasty after the 15th century and had been taken from the ducal coat of arms. Wartislaw I (around 1091 – died August 9, 1135) was the first historical ruler of the Duchy of Pomerania and the founder of the Griffin dynasty. The most prominent Griffin was Eric of Pomerania, who became king of the Kalmar Union in 1397, thus ruling Denmark, Sweden and Norway. The last Griffin duke of Pomerania was Bogislaw XIV, who died during the Thirty Years' War, which led to the division of Pomerania between Brandenburg-Prussia and Sweden. Duchess Anna von Croy, daughter of Duke Bogislaw XIII and the last Griffin, died in 1660.