Complex sentence: The Dawes brothers were persuaded to build an iron works adjacent to the iron fields, which became known as the Trent Ironworks, and construction began in 1862, the first cast being made on 26 March 1864.
Split into simpler sentences: The Dawes brothers were persuaded to build an ironworks adjacent to the iron fields, which became known as the Trent Ironworks. Construction began in 1862, the first cast being made on 26 March 1864.