Complex sentence: In 1771, when Johann Friedrich Struensee took over the de facto rule of Denmark-Norway, Johan Ernst Gunnerus was summoned to Copenhagen, where he was given the mission to establish a university in Norway.
Split into simpler sentences: In 1771, when Johann Friedrich Struensee took over the de facto rule of Denmark-Norway, Johan Ernst Gunnerus was summoned to Copenhagen. Here, he was given the mission to establish a university in Norway.