Complex sentence: During the 18th century, the east wing of the house was demolished leaving the U-shaped plan seen today, but in 1881 a major fire destroyed the south wing and caused extensive damage to the central section.
Split into simpler sentences: During the 18th century, the east wing of the house was demolished leaving the U-shaped plan seen today. In 1881, a major fire destroyed the south wing and caused extensive damage to the central section.