During the
Livonian War, on 10 June 1570, Duke Magnus arrived in
Moscow with the approval of his older brother, where he was crowned
King of Livonia by
Ivan IV of Russia. Magnus took the oath of allegiance to Ivan as his overlord and received from the corresponding charter for the vassal kingdom of Livonia in what Ivan termed his patrimony. The treaty between Magnus and Ivan IV was signed by an
oprichnik and by a member of the
zemskii administration, the
dyak Vasily Shchelkalov. The territories of the new kingdom still had to be conquered, but even so
Põltsamaa Castle was proclaimed the future official residence of the king. The newly crowned king Magnus of Livonia left Moscow with 20,000 Russian soldiers with the intention of conquering Swedish-controlled
Reval. Ivan's hope of the support of
Frederick II of Denmark, the older brother of Magnus, failed. By the end of March 1571, Magnus gave up the struggle for Reval and abandoned the siege. Magnus spent the last six years of his life at the castle of
Pilten in the
Bishopric of Courland, where he died as a pensioner of the
Polish crown. In 1662, Magnus' body was returned to Denmark and was reburied in the
Roskilde Cathedral. ==Spouse and issue==