Complex sentence: Thomas Wilson Barnes (1825--74) was an English chess master, one of the leading British masters at the time of Paul Morphy's visit to the UK in 1858.
Split into simpler sentences: Thomas Wilson Barnes (1825--74) was an English chess master, one of the leading British masters of his time. Barnes was one of the leading British chess masters at the time of Paul Morphy's visit to the UK in 1858.