The manor at Aldermaston became the property of Sir Robert Archard in about 1115 as a gift from King Henry I, though there are no surviving descriptions of a house. In 1361, the estate passed to the De La Mare family, who built a house next to the parish church. The house is likely to have been a quadrangular building, which was popular in the late 14th century.
In the early 16th century, the estate passed to Sir George Forster, by virtue of his marriage to the sole surviving De la Mare. There is evidence that the Forster family entertained Queen Elizabeth I on at least one occasion. The Forsters were supporters of the Royalist cause in the English Civil War. The Earl of Essex, commanding Parliamentarian forces, occupied the village in 1644.
The estate passed to the Congreve family in 1752. A stable block was built in about 1800, which is still standing, though used as offices. The estate remained with the Congreve family until 1843, when the house was badly damaged by fire.
At the time Humphrey Forster re-built the estate in 1636, a U-shaped lodge was built at the north-east of the estate. In the early 18th century, the centre section of the building was removed to convert the lodges into a pair of gatehouses. In the early 19th century, the original gates were replaced with a pair of wrought-iron gates that came from Midgham House.
Daniel Higford Burr bought the estate in 1849. He and his wife Mary built Aldermaston Court about 50 metres south of the previous house. They built the house in the Elizabethan style, and incorporated the figured wooden staircase, some stained glass, and the 14th century chimneys from the previous house, which was later demolished.
Charles Keyser bought the house in 1893 and lived there until his death in 1929. The house was empty for ten years before being bought by a company, Associated Electrical Industries (A.E.I.). Shortly after the outbreak of World War II, the British government requisitioned the estate. During the war, the USAAF HQ IX Air Support Command was stationed at the house, and there were anti-aircraft batteries stationed on the grounds. After the war, the estate was returned to A.E.I., who used it as a research laboratory.
Collier Macmillan Schools bought the estate in 1965. In 1967, the house became a Grade II* listed building. Blue Circle Industries bought the estate in 1981. They restored the house, and converted its usage into a hotel and conference centre. They also built an office complex on the estate next to the stable block, called Portland House, which won an award from The Concrete Society in 1986.
Holaw (420) Ltd., the present owners, bought the estate in 1997. The house, now formally known as 'Aldermaston Manor', continues to operate as a hotel and conference centre, and also as a popular venue for weddings. It is managed by the Compass Group of companies.