The Chōshū Five (長州五傑 Chōshū Goketsu?) were members of the Chōshū han of western Japan who studied in England from 1863 at University College London under the guidance of Professor Alexander William Williamson. It was still illegal to leave Japan when they left, as the maritime seclusion policy (sakoku or as it was known at the time kaikin ) was still enforced until 1866.
A Mr. Weigal, manager for Jardine, Matheson & Co. in Yokohama, put the Chōshū youths, disguised as English sailors, aboard a reluctant Captain J. S. Gower's vessel for 1000 ryō each, bound for Shanghai where they were sheltered on an opium storage ship before dividing into two groups for the long voyage to London.
When they reached London the Chōshū students were introduced by William Matheson to Professor Alexander Williamson.
Inoue Kaoru and Itō Hirobumi, destined to be two of the greatest Japanese statesmen of the age, worked as deckhands aboard the 1500 ton steamer Pegasus on the voyage to Europe. They also returned earlier than the other three when they realised that the Chōshū clan was in danger of attack by the Western allied powers for trying to close the Straits of Shimonoseki to foreign shipping.
2013 was the 150th anniversary since the Choshu Five had studied abroad at University College London (UCL). There were several celebrations in Japan and the UK. In July, there was a celebration by UCL and the Japan embassy in London. This celebration took place in UCL.