King John III of Sweden was a monarch who ruled from 1568 to 1592. He was born on December 20, 1537, and was the son of Gustav I of Sweden. John III is known for his efforts to strengthen the Swedish crown and for his attempts to promote the Protestant faith in Sweden. During his reign, John III faced challenges from both internal and external forces, including conflicts with Denmark and Russia. He is also recognized for his cultural contributions, including the promotion of the arts and the establishment of the University of Uppsala. His reign ended with his death on November 17, 1592.