The modern tourist centre of Vadstena in Östergötland, Sweden, with the 16th century Vadstena Slott (or Castle) built by Gustavus Vasa in 1545, was first mentioned in the early 14th century as the site of the Convent of St. Birgitta (Bridget) of Sweden, founder of the Brigittine Order and a mystic whose revelations were influential during the Middle Ages. The Convent in Vadstena was the most important medieval cloister in Sweden and was founded around 1370.

Birgitta or Bridget (also spelled Birgit, or Brigid, and in Swedish Sankta Birgitta av Sverige), a patron saint of Sweden, was born around 1303. She was the daughter of Birger Persson, governor of Uppland, and in 1316 she married Ulf Gudmarsson, later governor of the province of Nericia (now called Närke). She bore eight children, including St. Catherine of Sweden. On the death of her husband in 1344, Birgitta retired to a life of penance and prayer near the Cistercian monastery of Alvastra on the lake shore of Vättern. She dictated the revelations that came to her to the prior, Peter Olafsson, and he translated them into Latin. One of the revelations was a command to found a new religious order. This she was not able to carry out until near the end of her life, receiving papal permission in 1370. Earlier, in 1350, Birgitta went to Rome and, except for several pilgrimages, remained there for the rest of her life, constantly accompanied by her daughter Catherine. In 1372 she visited the Holy Land. St. Birgitta died in Rome, Italy, on 23 July 1373 soon after her return from the Holy Land. She was canonised on 8 October 1391. The feast day associated with St. Birgitta is 23 July (formerly 8 October).

Catherine, or Katarina Ulfsdotter, was the daughter of St. Birgitta, whom she succeeded as superior of the Brigittines. Catherine was born in Sweden around 1331. She married Egard Lydersson von Kyren, who died shortly after she left for Rome to join her mother as her constant companion. Catherine did not return to Sweden until after Birgitta's death in 1373. She took part in the ecclesiastical controversies of the time, supporting Pope Urban VI against the antipope Clement VII in Avignon, and she promoted the canonisation of Birgitta. Catherine was abbess of Vadstena when she died. Although she was never formally canonised, she is listed in the Roman martyrology. Catherine died in Vadstena on 24 March 1381. The feast day associated with her is 24 March (in Swedish, Sankta Katarina).