Daniel Mendoza was born in Whitechapel, Aldgate, London, England, on 5 July 1764, to a family of Spanish and Portuguese Jews, also known as Sephardim.

Jewish scholar Albert Hyamson wrote that Aaron Mendoza, a ritual slaughterer or shochet, who had written a book on his craft in 1773, was his grandfather.

[9] He grew up in London's East End in poor surroundings and worked as a glass cutter, labourer, assistant to a green grocer, and actor before taking up boxing as a profession.

On July 1786 [16] Mendoza fought a rematch against Tyne at Duppas Hill, Croydon, having dispatched a couple of minor fighters in the intervening eight months.

[18] After his fight with Sam Martin the Bath Butcher in Barnet on 17 April 1787, which Mendoza won in ten rounds and a total of 26 minutes, he was transported home followed by a cheering crowd who carried lighted torches and sang 'See the Conquering Hero Comes'.

The recognition by royalty annoyed his second, occasional manager Richard Humphries, who became a rival and planned for a match, but it elevated the stature of Jews in London.

[24] According to his own account, Mendoza slipped on the wet boards of the ring and badly sprained his ankle, preventing him from continuing, and requiring him to forfeit the bout.

At least seven English newspapers of the era, including London's Times and Chronicle, published articles on the Mendoza–Humphries bouts, and United States papers ran stories as well.

It was clear early in the fight that Mendoza's hand and foot work were vastly superior to Humphries', though both men were accomplished scientific boxers and had studied each other's style.

Poems and songs were written of Mendoza, he sat for portraits, and was asked to give boxing exhibitions at London's prestigious Covent Gardens.

Mendoza was paid 50 English pounds, an impressive sum in 1790, for several of his boxing demonstrations at Covent Gardens, which he conducted as often as three times a week.

[31] The anonymous work Pancratia (1812) noted that ‘In his manner there is more neatness than strength, and it has been said, more show than service; his blows are in general deficient in force, but given with astonishing quickness, and he is [agreed] to strike oftener, and stop more dexterously, than any other man.’[32] Other attributes considered typical of Mendoza’s style were: ‘stopping and returning with the same hand’,[33] and extensive use of the ‘chopper’ (a backhanded punch, often delivered with the same hand that had just been used to make a block).

The Modern Art of Boxing (a slim 48 page tome) is described by Mendoza as ‘a selection from different works on the same subject’ (it contains material taken directly from, for example, Godfrey’s 1747 treatise on self-defence).

Though he remained an admired and heroic figure, Mendoza's decline in popular support may have partly been due to public knowledge of several crimes he committed, which he omitted from his memoirs.

[42][43] After a stay in a debtors' prison, he resumed training and defeated Bill Warr again on 12 November 1794, outclassing him in only seventeen minutes at Bexley Common.

At a muscular twenty-six, Jackson was five years younger than Mendoza's thirty-one, four inches (10 cm) taller, and 42 pounds (19 kg) heavier.

Jackson, however, won in nine rounds, paving the way to victory by muscling Mendoza into the corner of the ring, grabbing his hair and pummeling his head with uppercuts using his free hand.

Many pugilists, such as James Figg and Jack Broughton, shaved their heads to avoid the possibility of this, until hair-pulling was eventually banned in boxing.

[45] Although Mendoza continued sparring tours well into the nineteenth century, 1795 marked the beginning of a steep decline in his popularity and for the most part, his income.

With great connections, though a convict, he was later appointed Sheriff's Assistant to the County of Middlesex in 1806, though he would have to evade prison again in later life due to mounting debts.

He turned down a number of offers for re-matches and in 1807 wrote a letter to The Times of London in which he said he was devoting himself chiefly to teaching the art of boxing.

In 1809 Mendoza and some associates were hired by the theatre manager John Philip Kemble of Covent Gardens in an attempt to suppress the Old Price Riots.

[49] He died on 3 September 1836 at the age of 72, reportedly at his home in Horseshoe Alley on London's Petticoat Lane, leaving his wife Ester and family of eleven in poverty.

Most modern sources [51][52][53][54][55] describe Mendoza as having been English Prizefighting Champion from 1792 (when he defeated Bill Warr at Smitham Bottom) to 1795 (when he lost to John Jackson at Hornchurch).

[57] Early 19th century works such as Pancratia (1812) and Boxiana (1813) also cover these fights without making any reference to the championship - and the lengthy chapter on Mendoza in Boxiana never refers to him having been champion (whereas the chapters on established champions such as Tom Johnson, Ben Brain and Jem Belcher make their statuses clear on multiple occasions).

[59] The championship then appears to have remained vacant until the advent of Jem Belcher in 1800, who is the next fighter to be described as Champion of England in the early prizefighting sources.