The first churches on site of St. Peter's Church were built during the Middle Ages (1128-1369), with famous church leader Bishop Otto von Bamberg resident in 1128, with services and baptisms being held in Wolgast. von Bamberg ordered the razing of the Pagan temple on the site and the construction of the first church, which is thought to have been comprised of wooden polls. With the conferral of a town charter by nearby power Lübeck in 1282, this church was replaced by a Brick Gothic hall church. Over the course of two centuries, between 1369 and 1554, this second St. Peter's was replaced by a third church bearing the same name, built as a court church for the Duchy in a three-aisled Brick Gothic form, complete with ambulatory and inner apse. Just before the end of the ongoing construction, the main aisle was extended west from the upper bay.
In the first half of the 15th century, the side aisles were installed and parts of the wall of former church were incorporated into the building. In the last quarter of the 15th century, two side chapels were added to the building's southern wing, only to be followed shortly thereafter by the Danish pillaging of the town.
History has not been kind to St. Peter's. in 1713, Tsar Peter I of Russia ordered the destruction of the town; St. Peter's was almost completely burnt to the ground, except for the southern side aisle and both southern chapels. The collapsed tower destroyed all the buildings vaulting apart from those in the remains of the church. The church was energetically rebuilt in the years thereafter, with the upper part of the spire rebuilt in an ortagonal form; a slanted roof complete with lighting and a peak was added in the later work.References:
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.