The earliest record of John Ernest Saur is dated 13 March 1767, when he enrolled as a freemason in Sheffield.  Unfortunately, he did not give his age, though his profession was described as ‘clerk’.  In the Sheffield directory (1787), Sauer, Eyre & Co was listed as a merchant at Union Street.  Sauer’s partner was John Eyre (though whether that was the John Eyre is unknown).  Sauer also apparently developed links with Jacob Roberts and Samuel Roberts (see Roberts, Cadman & Co).

In 1791, Sauer, Eyre & Co was dissolved by partners John Sauer, John Eyre, and Samuel Roberts.  The dissolution notice listed John Sauer and Samuel Roberts as the executors of Jacob Roberts.  Sauer and Eyre continued to trade as Sauer, Eyre & Shepherd, merchants, Norfolk Street.  The new partner was probably Benjamin Shepherd.  The enterprise exported ivory table knives and forks, desserts, carvers, and corkscrews to India (Calcutta Gazette, 11 December 1800).  John Ernest Sauer, merchant and factor, died on 23 November 1800 (Hull Packet, 2 December 1800).  He was buried at Dronfield.  He left under £5,000 to his widow, Ann (of which £100 was earmarked for his brother, John Sauer).  In 1808, she married Rev.  John Barber, a Methodist preacher.  Eyre & Shepherd continued to trade as a merchant at Norfolk Street, though by 1816 Benjamin Shepherd was listed alone.