De Pury was born on 19 January 1709 in Neuchâtel, Kingdom of Prussia (in present-day Switzerland), one of eight children of the geographer and explorer Jean-Pierre Pury and Lucrèce Chaillet.
His father, with the permission of English colonial governor Robert Johnson, founded the Colony of Purrysburg, a colony in the British Empire for Swiss Protestants, in present day South Carolina.
De Pury's father died in Purrysburg, and was succeeded by his elder son Charles.
Charles de Pury was killed during a slave revolt in the colony in 1754.

In 1725 de Pury left Switzerland and moved to Marseille, France where he worked in maritime trade with the merchant Isaac Tarteiron for three years.
In 1730 he was hired by the South Sea Company, trading imported goods from African and American ports.
The South Sea Company was active in the Atlantic slave trade.
His success as a businessman in the company led to him obtaining British citizenship.

In 1736 he moved to Lisbon, Portugal and co-founded, with Joseph Mellish, a bank called Pury, Mellish, & Devismes.
From Portugal, de Pury established a business importing diamonds from Brazil, trading them in London's financial center.
He also became involved in the trading of woods from the Amazon rainforest, including mahogany and jacaranda.
In 1762 he was appointed a banker to Joseph I of Portugal.

He bequeathed a large part of his fortune to the city and the bourgeoisie of Neuchâtel, used to repair buildings and churches, fund the construction of the town hall, establish local charities, build a public library, and build schools and hospitals.
The sum of the inheritance the city received was the modern equivalent of CHF 600  million.

In 1785 de Pury was ennobled to the rank of freiherr by Frederick II of Prussia.
He died on 31 May 1786 in Lisbon.
He is buried at the English cemetery at St. George's Church.
De Pury was born on 19 January 1709 in Neuchâtel, Kingdom of Prussia (in present-day Switzerland), one of eight children of the geographer and explorer Jean-Pierre Pury and Lucrèce Chaillet. His father, with the permission of English colonial governor Robert Johnson, founded the Colony of Purrysburg, a colony in the British Empire for Swiss Protestants, in present day South Carolina. De Pury's father died in Purrysburg, and was succeeded by his elder son Charles. Charles de Pury was killed during a slave revolt in the colony in 1754.
In 1725 de Pury left Switzerland and moved to Marseille, France where he worked in maritime trade with the merchant Isaac Tarteiron for three years. In 1730 he was hired by the South Sea Company, trading imported goods from African and American ports. The South Sea Company was active in the Atlantic slave trade. His success as a businessman in the company led to him obtaining British citizenship.
In 1736 he moved to Lisbon, Portugal and co-founded, with Joseph Mellish, a bank called Pury, Mellish, & Devismes. From Portugal, de Pury established a business importing diamonds from Brazil, trading them in London's financial center. He also became involved in the trading of woods from the Amazon rainforest, including mahogany and jacaranda. In 1762 he was appointed a banker to Joseph I of Portugal.
He bequeathed a large part of his fortune to the city and the bourgeoisie of Neuchâtel, used to repair buildings and churches, fund the construction of the town hall, establish local charities, build a public library, and build schools and hospitals. The sum of the inheritance the city received was the modern equivalent of CHF 600  million.
In 1785 de Pury was ennobled to the rank of freiherr by Frederick II of Prussia. He died on 31 May 1786 in Lisbon. He is buried at the English cemetery at St. George's Church.
David de Pury