Giles was born in Sutton, the fourth son of Herbert Giles and his first wife Catherine Fenn. Educated privately in Belgium, Austria, and Scotland, Giles studied Classics at Wadham College, Oxford, graduating BA in 1899.
The 1910 Giles translation of The Art of War succeeded British officer Everard Ferguson Calthrop's 1905 and 1908 translations, and refuted large portions of Calthrop's work. In the Introduction, Giles writes:
It is not merely a question of downright blunders, from which none can hope to be wholly exempt. Omissions were frequent; hard passages were willfully distorted or slurred over. Such offenses are less pardonable. They would not be tolerated in any edition of a Latin or Greek classic, and a similar standard of honesty ought to be insisted upon in translations from Chinese.
Sinology
Lionel Giles used the Wade-Gilesromanisation method of translation, pioneered by his father Herbert. Like many sinologists in the Victorian and Edwardian eras, he was primarily interested in Chinese literature, which was approached as a branch of classics. Victorian sinologists contributed greatly to problems of textual transmission of the classics. The following quote shows Giles' attitude to the problem identifying the authors of ancient works like the Lieh Tzu, the Chuang Tzu and the Tao Te Ching:
The extent of the actual mischief done by this "Burning of the Books" has been greatly exaggerated. Still, the mere attempt at such a holocaust gave a fine chance to the scholars of the later Han dynasty, who seem to have enjoyed nothing so much as forging, if not the whole, at any rate portions, of the works of ancient authors. Some one even produced a treatise under the name of Lieh Tzu, a philosopher mentioned by Chuang Tzu, not seeing that the individual in question was a creation of Chuang Tzu's brain!
Continuing to produce translations of Chinese classics well into the later part of his life, he was quoted by John Minford as having confessed to a friend that he was a "Taoist at heart, and I can well believe it, since he was fond of a quiet life, and was free of that extreme form of combative scholarship which seems to be the hall mark of most Sinologists."