Sigfrids work was mostly confined to the mid-southern province of Sweden called Småland, as well as some work in the province around the Swedish west coast. The first Christian King of Sweden, King Olof “the Donor”, is thought to have been baptized by Sigfrid. The same king gave various lands and farms to the church as donations, hence the name “the Donor”. With these gifts King Olof created a more stable economic base on which to build the ongoing mission work.
Sigfrid converted many heathens to Christianity and baptized them. Many different springs around the south-west bear his name, as he is said to have baptized many converts in them. At these places he also stayed for extended periods of time, building up diocesan centers. Eventually he was informed that his three brother monks had been martyred in Småland where they had stayed to run the mission. He returned and continued their work. They had, among other things, established a Christian parish in Växjö, and built a church there.
According to legend, Unaman’s, Sunaman’s and Vinaman’s murderer had ordered that they be beheaded, and had placed their heads in a basket together with a heavy rock, throwing it into a lake. When Sigfrid arrived in the area he prayed to God that he might find the heads of his three friends. One night while he was walking alone in the woods, he saw three beacons of light floating across the water, coming towards shore. Sigfrid was curious, and so he took off his shoes and waded out into the water towards the light. Under the light he saw the basket with their heads floating towards him. Sigfrid interred the relics in the church in Växjö. When icons were later painted of Saint Sigfrid he was often depicted holding the basket with the three heads. King Olof “the Donor” came to Växjö soon after he heard about the death of the martyrs. His intention was to execute the murderers, but he was prevented by Sigfrid who plead for mercy on their behalf. The murderers were fined instead. The money from the fines was used to build up the diocese in Småland, where Sigfrid continued his missionary work.
Sigfrid died in Växjö on the 15th of February, and was soon revered as a saint. His relics are still there. The veneration of Saint Sigfrid has been very popular ever since, and he is considered one of the chief protectors of Sweden.