While most of the political and military commanders whom we now call 'great' were often ruthless or megalomaniacs, Korean Admiral Yi Sun-sin is remembered not only for his military prowess but also for his integrity and humility. He came to his nation's rescue in extremis when others had failed.

The 15th and 16th century saw unprecedented creativity in naval warfare. The Chinese, Portuguese, Spanish, English, Japanese and Koreans each employed their first blue water navies in distinct ways, for distinct strategic purposes, and with distinct technological innovations. In 1592, Admiral Yi Sun-sin answered the call to rescue his country from invasion, despite having been undeservedly court-martialled twice and reduced to the ranks by hostile superiors who were jealous of his abilities. Vastly overmatched, with only a dozen innovative 'turtle ships' and some support from Chinese naval forces, he defeated the Japanese fleet, isolating the Hideyoshi army and ending the Imjin War – a triumph that cost him his life.

Lt Cdr Dr Seok Yeong-dal teaches naval history and strategy at the Republic of Korea Naval Academy. His PhD from Yonsei University in Seoul examined the successes and limitations of the Royal Navy's reforms in the 19th century. He has written extensively on Admiral Yi, as well as on the Royal Navy in the 19th century with his recent book, A Failed Reform or The First Steps of Reforms, Achievements and Limitations of the Royal Navy's Reforms in the 19th Century, published in South Korea in 2023.