The construction of the church of St. James probably began around 1370. The main part of the work, that is the nave and the ground floor of the tower with chapels, was probably completed in 1380. In the 16th century vaults were given, and in 1596 the tower was raised to 7 storeys. In the 17th century, due to the impoverishment of the parish, the interior of the church and its walls remained neglected. It was not until 1721 that Piotr Olchowski from Reszel reconstructed the two falling into ruin chapels. The church was severely affected by the quartering of Napoleonic troops in 1807. In 1819, the vault over the organ gallery collapsed, and in 1864 the entire building was in danger of collapsing and had to be closed. The church was put into use after a general renovation carried out in the years 1866-1868, but the work on the interior lasted a dozen or so years longer. During World War II, the church was saved from destruction by Fr. Jan Hanowski, who managed to get the Russians to save the temple.
The church was erected in the gothic style, made of brick on a stone foundation. It is a three-nave, six-span, hall with no separate chancel. The temple’s corpus consists of a 58×24 meter nave, a tower with a height of 70 meters and two adjoining chapels. The massive, monumental building originally did not have any outbuildings, even the sacristy was placed inside the south aisle. From the eastern side, there is a gothic gable decorated with pinnacles and blendes, above which there are round holes protruding above the roof (a motif also found in the Kwidzyn cathedral and in the Olsztyn castle). Gable height reaches 38 meters. The nave corpus is enlived by the rhythm of buttresses and pointed windows with tracery.
The tower has seven storeys separated by horizontal, plastered stripes, which up to the third floor are decorated with glazed tracery. All its walls are decorated with two-arch blendes. The highest storey is topped with an arcaded frieze and cornice. In the center of the facade there is the main entrance to the church, a richly profiled, pointed portal.
In the central nave, the corpus is covered with a net vault and diamond vault in the aisles. The vault supports are designed in the form of polychrome, bearded male heads, made of terracotta.
Grzybkowski A., Gotycka architektura murowana w Polsce, Warszawa 2016.
Lesiński A., Olsztyńska bazylika katedralna św. Jakuba na przełomie wieków, Olsztyn 2009.
Website katedra.olsztyn.pl, Rys historyczny.