The Trinity Church — known as the German Church — stands opposite Fredrikskyrkan on Stortorget and tells a story about the cosmopolitan workforce that built the Swedish navy. When Karl XI founded Karlskrona, he recruited craftsmen and sailors from across northern Europe — German, Dutch, English, and Danish workers who needed their own place of worship. Trefaldighetskyrkan was their church, built in 1709 for the city's non-Swedish Protestants.
The building is architecturally similar to Fredrikskyrkan but slightly smaller, and together the two churches give Stortorget its balanced, theatrical quality. The interior has been modified over the centuries but retains its original proportions. Today it serves the Swedish Church alongside Fredrikskyrkan and is open to visitors. The contrast between this church's history of immigrant labour and the monumental square it faces is one of those small ironies that makes Karlskrona's history worth thinking about.