Complex sentence: With the castle acting as overflow accommodation, the main party was settled into Haus 2/the casino, including Generals Jodl, Keitel, Blumentritt, von Manteuffel and S.S. Colonel Sepp Dietrich.
Split into simpler sentences: With the castle used to provide for overflow accommodation, the main party settled into Haus 2/the casino. Those present included Generals Jodl, Keitel, Blumentritt, von Manteuffel and S.S. Colonel Sepp Dietrich.