Complex sentence: Before being demolished, Hamilton Palace was one of only two non-royal residences in the United Kingdom that bore the word palace in its name, the other being Blenheim Palace, the ancestral seat of the Dukes of Marlborough.
Split into simpler sentences: Before being demolished, Hamilton Palace was one of only two non-royal residences in the United Kingdom that bore the word palace in it's name. The other being Blenheim Palace, the ancestral seat of the Dukes of Marlborough.