Complex sentence: In the 1820s John Henry Burges moved in and enlarged the cottage, and his son John Ynyr Burges commissioned architect Thomas Duff to design a new mansion, which was built between 1839 and 1854, which he renamed Parkanaur.
Split into simpler sentences: In the 1820s, John Henry Burges moved in and enlarged the cottage. His son, John Ynyr Burges, commissioned architect Thomas Duff to design a new mansion, which was built between 1839 and 1854, which he renamed Parkanaur.