Chevalier: Le Chevalier D'Eon (シュヴァリエ, Shuvarie?) (French meaning: D'Eon the Knight) is a 24-episode anime TV series based on Tow Ubukata's historical fantasy novel of the same title, produced by Production I.G. It has aired in Japan on WOWOW and Animax, broadcast the series across its respective networks worldwide, including its English language networks in Southeast Asia and India, as well as other networks in Taiwan, Hong Kong and other regions. The series was originally licensed to the North American market by ADV Films; in 2008, it became one of over 30 titles transferred from ADV to Funimation Entertainment. The novel has been previously adapted as manga, written by Kiriko Yumeji and Tow Ubukata.

The story is loosely based on the historical figure Chevalier d'Eon, who lived in the middle of 18th Century, pre-revolution France under the reign of Louis XV.

Source: Wikipedia