[3][4] The foundation stone of the new concrete and glass County Hall was laid by the Lord Lieutenant of Buckinghamshire, Sir Henry Floyd, on 22 October 1964.

While its design is a bold conception freely using works by such architects as Frank Lloyd Wright, Le Corbusier and the characteristics of De Stijl and it has similarities to Paul Rudolph's School of Art and Architecture at Yale completed in 1963.

However, as early as 1904 Auguste Perret designed a block of flats in the Rue Franklin, Paris which has similar angles, bayed windows and canted recesses to County Hall in Aylesbury,[9] and these flats too were constructed of concrete.

With its Brutalist roots in the 1940s, and earlier, Aylesbury's County Hall was, like its classical predecessor, already dated by the time of its 1966 completion: by then architecture was moving on to the cleaner and straighter lines and sheets of plate glass advocated by such architects as Mies van der Rohe.

[10] Works of art in County Hall include a portrait by Godfrey Kneller of John Egerton, 3rd Earl of Bridgewater,[11] a portrait by Joshua Reynolds of George Nugent-Temple-Grenville, 1st Marquess of Buckingham[12] and a painting by Peter Paul Rubens depicting a hunting party being attacked by wolves.