Complex sentence: Together they formed "Hewlett and Blondeau" and built Farman, Avro, Caudron and Hanriot aircraft under licence, they were the first company to build Caudron in Britain.
Split into simpler sentences: Together they formed "Hewlett and Blondeau" and built Farman, Avro, Caudron and Hanriot aircraft under licence. They were the first company to build Caudron aircraft in Britain.