The article examines the building history of Brunflo church and the origins of its large adjacent freestanding tower. Previous scholars have characterised the cruciform phase of Brunflo church as Romanesque, partly inspired by Gamla Uppsala cathedral. However, the article argues that the church probably underwent two phases of construction in the Middle Ages, one in the 12th century and one probably in the 15th or early 16th century.

Some previous scholars have characterised the tower as defence tower (Swedish kastal), whereas others have pointed out its lack of defensive features. The article demonstrates that the timber structure at the top of the tower is partly original. This construction resembles certain types of medieval Swedish timber bell tower, specifically the upper part where the bells hang. The author thus concludes that the Brunflo stone tower was originally built as a bell tower, as well as being a storehouse for valuable goods. Traces of storage space survive in the tower.

The article also presents a dendrochronological study of the above timber structure, showing that the tower was built in the mid-13th century.

When attempting to place these buildings in an historical context, the author concludes that although the origins of the earliest stone church remain obscure, the tower was probably built when Jarler (d. 1255) was archbishop of Uppsala. Given that the medieval archdiocese of Uppsala owned Södergård farm, adjacent to Brunflo church, the archbishop probably had a hand inbuilding the tower. The later expansion of the church, to include a new chancel and transepts to accommodate side altars, may be seen against the backdrop of the growing cult of saints in late-medieval Scandinavia.