Prince Ulrik John of Denmark was the song of Frederick II of Denmark, the King of Denmark and which other country?
Frederick II of Denmark Frederick II (1 July 1534 – 4 April 1588) was King of Denmark and Norway and duke of Schleswig from 1559 until his death.
John, Prince of Schleswig-Holstein Johan of Schleswig-Holstein (9 July 1583 – 28 October 1602) was the youngest son of Frederick II of Denmark and Norway and Sophia of Mecklenburg-Schwerin. He went to Russia in 1602 as the bridegroom of Boris Godunov's daughter Ksenia (Xenia), but fell ill and died before the marriage could take place.