Complex sentence: As the last of the family line of Kaunitz-Rietberg he died in Palais Kaunitz, Mariahilfer and was buried in the family grave in Austerlitz.
Split into simpler sentences: As the last of the family line of Kaunitz-Rietberg he died in Palais Kaunitz, Mariahilfer. He was buried in the family grave in Austerlitz.