Jacob Kettler was Duke of Courland and Semigallia from 1642 to 1682. Under his rule, Courland and Semigallia became more independent of its Polish suzerain, reached its peak in wealth, and even engaged in its own overseas colonization, making it one of the smallest, but fastest growing states in the world at that time.
- Occupation
- regent
- Position held
- regent
- Born
- October 28, 1610
- Died
- January 1, 1682, December 31, 1682
