Complex sentence: With the arrival and government of the Teutonic Knights in Prussia, they built a "Hof" (estate) near the site of the Prussian "Burg" (castle) Cadina, where they held court over the native Old Prussian inhabitants in this area.
Split into simpler sentences: With the arrival and government of the Teutonic Order in Prussia, they built a Teutonic Order Hof (estate) near the site of the Prussen Burg (castle) Cadina. At this Teutonic Order Hof site the Order held court over the native Old Prussian inhabitants in this area.