It faced the Inland Sea and bordered on Awa and Iyo Provinces. Across Naruto strait it bordered Awaji Province too. Administratively it was included as a part of Nankaidō. It was settled in the 7th century and originally consisted of the northeastern part of Shikoku and Awaku Islands on the Inland Sea.
Sanuki's ancient capital is believed to have been near modern Sakaide, but has not been discovered. Takamatsu developed as the main seat of the province in the Middle Ages.
In the Classical Period, Sanuki was famous for its associations with the Buddhist monk, Kūkai, as both his birthplace and early upbringing. Later, the famed poet Sugawara no Michizane served as governor of the province from 886 to 890 under the Ritsuryō Codes.