Complex sentence: In the 19th century the dioceses of the Church of England began gradually to come under review again, however an increase in the bench of bishops was not considered politically expedient, and so steps were undertaken to prevent it.
Split into simpler sentences: In the 19th century the dioceses of the Church of England began gradually to come under review again. However an increase in the bench of bishops was not considered politically expedient, and so steps were undertaken to prevent it.