He was involved with the stock market flotation of several large privately owned retail stores, including Harrods in 1889 and D H Evans in 1894.
His father was connected with shipping and the holder of a Masters Certificate; his grandfather had been involved with the whale fisheries industry.
In 1874, they purchased a diving cutter and specialised in salvage, raising or breaking-up sunken ships that were a danger to navigation.
Whilst chairman of Harrods he also oversaw the purchase of the departmental stores Dickins & Jones (1914) and Swan and Edgar (1920).
However, at the same time he came under scrutiny for a share flotation that he had been involved with concerning another store called Grice and Son of Clapham.
This business had been purchased by Industrial Contract Corporation (Limited) for the sum of £16,000 in about 1897, and sold to another company with the same directors called the Auxiliary Stores for £48,000 (equivalent to £6,560,000 in 2023).
A merchant and banker named William Mendel was also a key player, holding the founders' shares that gave him a controlling interest.
In order to allow a public examination of the matter, Newton instigated formal winding up proceedings to be heard before a Chancery judge.
In December a proposal was put forward that the City of London should sponsor a volunteer troop of soldiers to take part in the conflict.
Lord Mayor Newton was approached by Colonel Boxall on the subject and within days he had reached agreement with various City livery companies, bankers, merchants and the Court of Common Council to support and fund the venture.
What made this speeding mobilisation possible was that the recruits were all members of the Metropolitan Volunteer Corp, part-time soldiers, recommended for their abilities by their respective commanding officers.
It was there on 20 October 1920 that Sylvia Pankhurst, a suffragette and editor of the newspaper The Workers Dreadnought, appeared before him accused of sedition.
The doctor who conducted the post-mortem said at the inquest that Newton's heart was in a poor condition and he would not have lived much longer, although the strychnine had contributed to the death.
Sir George Peter Howgill Newton, the 4th baronet (born 1962), is the vicar of Holy Trinity church in Aldershot.