Jacob Kettler was a Duke of the Duchy of Courland and Semigallia (1642–1682). Under his rule, the duchy was brought to its greatest peak in wealth and engaged in colonization.

Life

Kettler was born in Goldingen (Kuldīga). He was the son of Wilhelm Kettler and Sofie Hohenzollern, Princess of Prussia, a daughter of Albert Frederick, Duke of Prussia. He was the godson of King James I of England. While his father was exiled from duchy Jacob lived in the courts of Stettin and Berlin. He had studied in the Rostock and University of Leipzig and was sympathizing to ideas of mercantilism. In 1634 Jacob traveled through the Europe. He visited Paris, London and studied shipbuilding in Amsterdam. In 1638 he became co-ruler of the duchy but in 1642 he became sole duke of Courland.

Under Kettler's rule, the duchy traded with nations like the Netherlands, Portugal, England, and France. He started large scale reforms of the duchy's economy. The Duke improved the agriculture, opened many manufactures and started active shipbuilding. During Jacobs reign the Duchy became de facto independent from the Polish crown because all contracts with foreign powers were signed as between independent countries. Since 1646 all customs administration of the Duchy also was in the Duke's power.

The Duchy was involved in the colonisation. In 1651 he sent a fleet to build Fort Jacob on the Gambia River on the island that would later be known as St. Andrews in West Africa. In 1654 he conquered Tobago with the Das Wappen der Herzogin von Kurland, a double decker ship which was armed with 45 cannons and carried 25 officials, 124 Courlander soldiers, and 80 families of colonists. The colony on Tobago was named Neu Kurland ("New Courland"). Duke Jacob joined the treaty of Westminster.

The Duke was taken prisoner by the Swedes from 1658 to 1660, during the Northern Wars. Together with his family, he was held captive in Riga and later in Ivangorod. During this time, his colonies were attacked and lost and his fleet destroyed. After the war ended, he rebuilt the duchy's fleet, and retook the island of Tobago from the Dutch. Some believe he also intended to colonize Australia, which had at that time been discovered and claimed by the Dutch whom he was at war with. He supposedly had the blessing of Pope Innocent X. However, the pope soon died, and the new pope was unwilling to support the plan. Rest of his reign he tried to reach pre-war level of wealth but managed to do this only partly. The Duke died in Mitau (Jelgava) on 1 January 1682. Jacob Kettler is remembered as fair ruler who was a friend of latvian peasants and even knew the latvian language

Issue

Kettler married Margravine Louise Charlotte of Brandenburg (1617–1676), the daughter of George William, Elector of Brandenburg and had issue:

• Ladislaus Frederick Kettler
• Frederick Casimir Kettler
• Charles Jacob Kettler
• Ferdinand Kettler
• Alexander Kettler
• Louise Elisabeth Kettler, Landgravine of Hesse-Homburg
• Christina Kettler
• Charlotta Maria Kettler, Abbess of Herford
• Marie Amalie Kettler, Landgravine of Hesse-Kassel