Complex sentence: After the extinction of the House of Than in 1603, Dahn was the head office of a department of the diocese of Speyer until the beginning of the French revolutionary wars in 1797/98.
Split into simpler sentences: After the extinction of the House of Than in 1603, Dahn was the head office of a department of the diocese of Speyer. This situation lasted until the beginning of the French revolutionary wars in 1797/98.