John Isaac Thornycroft built his first vessel at Chiswick on the River Thames in the late 1800's, and was a pioneer in the production of high speed vessels.
Thornycroft specialised in the development of fast torpedo boats and destroyers achieving speeds that were previously considered unobtainable.
The main JI Thornycroft yard was established on the banks of the River Itchen at Woolston, Southampton and continued to serve the company until the new shipbuilding facility in Portsmouth Dockyard was constructed in 2003.
The city shipyard was always one of Southampton's major employers, and delivered its first ship to the Royal Navy, HMS Tartar in 1906. In the period up to the start of the First World War, Thornycroft's built 37 destroyers for the RN alone, and several more for export.
A Thornycroft built ship was always considered by Royal Navy sailors to be strongly built as the vessels proved to be well able to take serious damage and still survive to fight another day.
During the First World War, Thornycroft built 26 destroyers, three submarines, and a huge number of coastal motor boats as well as fast launches able to carry torpedoes.
Knighted in 1902 JI Thornycroft had been born in Rome and his parents were the sculptors, Mary and Thomas Thornycroft.
John Isaac Thornycroft died in 1928.