King Birger of Sweden, also known as Birger Jarl, was a prominent figure in the 13th century, serving as a regent and military leader. He played a crucial role in the establishment of the Swedish state and is often credited with founding the city of Stockholm. His leadership helped to consolidate power and expand the territory of Sweden during a time of political fragmentation. Birger was born around 1210 and became the de facto ruler of Sweden after the death of his brother, King Erik XI. He was instrumental in the creation of the Swedish nobility and the legal framework that governed the kingdom. Birger's legacy is remembered for his contributions to the development of Sweden as a unified nation.