William Paxton was born in 1744, the son of John Paxton, chief clerk to rich Scottish wine merchant Archibald Stewart.

The family moved to London when Paxton was three years old.

At the age of twelve Paxton joined the Navy as a captain`s boy on HMS St Albans.  In 1760 he joined HMS Thunderer as Midshipman, the lowest officer rank.   In 1764, at the age of twenty, Paxton left the Navy to join a private British merchant ship as a `free mariner` based in India.

In 1772 Paxton returned to England to train as an assayer (a valuer of coins) in order to help to control the monetary situation in Bengal.  Two years later Paxton became Assay Master to the Bengal Presidency.  In 1778 Paxton became Master of the Mint.   During this time Paxton began to work for colleagues and friends as an Agent.  He generated his own fortune by charging commission on the financial transactions made on their behalf.   In 1785 Paxton returned to London to establish his agency there.  During the 6 month journey home he met Welshman David Williams with whom he became friends and from whom he received an invitation to visit Wales.  Shortly after his return Paxton`s agency established itself as a merchant bank.

Paxton married Ann Dawney in 1786 and their first child was born a year later.  Paxton was to have another ten children.

In 1789 Paxton bought the Middleton Hall estate for about £40,000.  (See `Middleton Hall.`)  The original Hall was turned into a Home Farm.  Between 1793 and 1795 a new Hall was designed and built by architect Samuel Pepys Cockerell.   Engineer James Grier was employed as estate manager and Samuel Lapidge, a surveyor who had worked with Lancelot `Capability` Brown, was hired to design the landscape and gardens.

In 1793 Paxton was admitted as a Burgess to Carmarthen Borough.

During the early 1790s Paxton had tried and failed to be elected to Parliament in Newark on Trent.

Paxton stood at the 1802 election in Carmarthenshire representing the Whig cause against the Tory James Hamlyn Williams.  In the run up to the election Paxton spared no expense.  He bought the voters 36,901 dinners and 25,275 gallons of ale, and spent £768 on blue ribbons, among other costs.   He lost the election by 46 votes.  Two months later he was elected Mayor of  Carmarthen.  Paxton took his lobbying duties seriously and brought pressure to bear to bring about the introduction of fresh piped water to Carmarthen.  He also started The Loyal Carmarthen Volunteers.

In 1803 Paxton was knighted.

In 1803 the MP John George Philipps resigned his seat in Parliament in favour of Paxton.  Three years later Paxton took the Carmarthenshire seat unopposed.  The following year an election was called but due to local opposition Paxton withdrew his candidacy.

Between 1806 and 1809 Paxton`s Tower was built probably to a design by Samuel Pepys Cockerell.  (See Paxton`s Tower).

Paxton died in 1824 at the age of 80 whilst in London.  He is buried in the catacombs at St. Martin in the Fields.  His wife died in 1846.