Charndon means ‘cairn hill’, cairn being a Celtic word for a ceremonial hill or pile of stones. The hamlet was recorded in the Doomsday Book in 1086 as Credendone. Charndon was part of The Hundreds of Buckingham.

Hundreds were first mentioned in the Laws of Edgar in 970, and by the time of Ethelred the term referred to an area of one hundred hides for the purpose of taxation. For many centuries after this the Hundreds were used as a fiscal, judicial and sometimes a military district. These units were thus used for the collection of Danegeld (later subsidies), and the holding of courts for both civil and criminal matters, originally these were held every month, then every fortnight and eventually after 1234 every three weeks. In addition, a sheriff would tour the county twice a year to hear special complaints. The meetings were usually held in the ‘open’ and at a well-known local landmark, such as an earthwork, tumulus, or tree, e.g., in the Cottesloe Hundred it was at a barrow, or, ‘low’ from which it takes its name, and for the Risborough Hundred was at the ancient earthwork of that name. Later hundreds usually met in a town or village.

In 1086 at the time of the Domesday Survey there were 18 hundreds in Buckinghamshire, and possibly even as early as that they had become grouped into threes. By the beginning of the fourteenth century, with one exception each had become a complete Hundred, thus reducing the total to eight. In 1086 the Hundreds were Stone, Risborough and Aylesbury (which became Aylesbury Hundred), Burnham, Desborough and Stoke (continued three separate Hundreds known as the The Three Hundreds of Chiltern), Ixhill, Ashendon and Waddesdon (which became Ashendon Hundred), Yardley, Cottesloe and Mursley (which became Cottesloe Hundred), Stodfold, Rowley and Lamua (which became Buckingham Hundred), and Bunsty, Seckloe and Moulsoe (which became Newport Hundred).