Jürgen von Farensbach was a Baltic German nobleman

Baltic Noble Corporations

Baltic Noble Corporations of Courland, Livonia, Estonia, and Oesel were medieval fiefdoms formed by German nobles in the 13th century under vassalage to the Teutonic Knights and Denmark in modern Latvia and Estonia...

 and Livonian

Livonian Confederation

Terra Mariana was the official name for Medieval Livonia or Old Livonia which was formed in the aftermath of the Livonian Crusade in the territories comprising present day Estonia and Latvia...

 general. Sent as the Ambassador of Livonian Confederation to Czar Ivan IV of Russia

Ivan IV of Russia

Ivan IV Vasilyevich , known in English as Ivan the Terrible , was Grand Prince of Moscow from 1533 until his death. His long reign saw the conquest of the Khanates of Kazan, Astrakhan, and Siberia, transforming Russia into a multiethnic and multiconfessional state spanning almost one billion acres,...

, for concluding a peace treaty, he entered the Russian service and won the battle on Oka

Battle of Molodi

The Battle of Molodi was one of the key battles of Ivan the Terrible's reign. It was fought near the village of Molodi, 40 mi south of Moscow, in July-August 1572 between the 120,000-strong horde of Devlet I Giray of Crimea and about 60,000 Russians led by Prince Mikhail Vorotynsky...

 against the Tatars on August 1, 1572. Later he served in the Danish and Polish armies.
In 1586 Farensbach gained the rank a senator of the Polish crown granted by Sigismund III, whom he had assisted in gaining the throne of Poland. As field marshal of Poland he fought against the Swedish Empire

Swedish Empire

The Swedish Empire refers to the Kingdom of Sweden between 1561 and 1721 . During this time, Sweden was one of the great European powers. In Swedish, the period is called Stormaktstiden, literally meaning "the Great Power Era"...

, where he was killed in the attack on the castle of Fellin on May 17, 1602.