Gustav I of Sweden, also known as Gustav Vasa, was a significant figure in Swedish history, reigning from 1523 to 1560. He is often credited with founding the modern Swedish state after leading a successful rebellion against Danish rule during the Kalmar Union. His leadership helped establish Sweden as an independent nation. During his reign, Gustav I implemented important reforms, including the establishment of a centralized government and the promotion of Protestantism, which led to the decline of Catholic Church influence in Sweden. His legacy is celebrated for shaping the country's political and religious landscape, laying the groundwork for future development.