According to historians interpreting the writings of Walter Map, it is likely that Beachley was the site of an unprecedented meeting around 1056 between the unchallenged ruler of Wales, Gruffydd ap Llywelyn, and the king of England, Edward the Confessor, to establish each one's areas of control.

It was recorded in the 12th century when the de Clares, lords of Tidenham, granted quittance of the passage to the monks of Tintern, and was evidently much used in 1405 when great numbers of the English and Welsh were said to resort to the nearby chapel of St Twrog.

The manor of Tidenham retained rights over the passage, and received rents from the parishes of Aust and Beachley, until the 19th century.

It was garrisoned by Royalists under Sir John Wintour, but was overrun in October 1644 by Parliamentary forces under Col. Edward Massey.

In 1915, during World War I, the government requisitioned a large area of land at Beachley and constructed National Shipyard No.2.

Instead, in 1924 it was decided to establish a British Army Apprentices School[8] (which in 1966 was renamed as an Army Apprentices College) at Beachley to ensure a core of qualified soldiers with excellent technical education combined with first class military training as potential NCOs and officers mainly for the specialist corps Royal Engineers, REME Plant Operator mechanics and RAOC.