On the death of WH Poynder the estate passed to a nephew, John Dickson Poynder. In 1884 he succeeded his uncle, Sir Alexander Collingwood Thomas Dickson, as sixth baronet and on succeeding to his maternal uncle’s property he assumed by royal licence the additional surname of Poynder in 1888.
It was during the ownership of Sir John Poynder Dickson Poynder that the house became a focal point for political, social and recreational life in North Wiltshire.
Sir John became MP for Chippenham in 1892 and a Member of London County Council from 1898 to 1904. He also served in the Second Boer War as aide-de-campe to Lord Methuen, Commander in Chief, winning a DSO in 1900.
There are records of Winston Churchill having stayed at Hartham Park over the Christmas of 1896, during the summer of 1897 and again in 1899, and subsequent correspondence between the two men continued for much of their lives.
Circa 1906 Sir John had Hartham Park significantly remodelled, and the house hosted a great many gatherings, including visits by the Prince Arthur, Duke of Connaught and Strathearn, the third son of Queen Victoria who was attracted by both the shooting and the golf locally.
The grounds were landscaped by Harold Peto and superb Dutch water gardens built (now, sadly, largely overbuilt as a result of 1960s development.)