Complex sentence: The university was founded in 1904 as Königliche Technische Hochschule zu Danzig, at which time Gdansk, then known as Danzig, was part of the German Empire.
Split into simpler sentences: The university was founded in 1904 as Königliche Technische Hochschule zu Danzig. At the time Gdansk, then known as Danzig, was part of the German Empire.