William Henry Fox Talbot (1800–1877), pioneer of photography, was the only child of William Davenport Talbot (1764–1800) of Lacock Abbey in Wiltshire, and Lady Elisabeth Theresa Fox-Strangeways (1773–1846), the eldest child of the second earl of Ilchester. William Davenport died when his son was five months old. In 1804, Lady Elisabeth married Captain (later Rear-Admiral) Charles Feilding (1780–1837) and had two daughters, Caroline Augusta Feilding, later Lady Mount Edgcumbe (1808–1881) and Henrietta Horatia Maria Feilding, later Gaisford (1810–1851).

Horatia Maria Gaisford [née Feilding] (1810–1851) was fond of music and fluent in French, having been tutored during her youth alongside her sister Caroline by their Parisian governess, Amélina Petit de Billier (d.1876). While her siblings married and left Lacock Abbey early in their lives, Horatia remained at the family home well into adulthood, enjoying social engagements and living on the continent for a period alongside her parents. Horatia enjoyed a good relationship with her brother Henry, as they shared many common interests, such as botony. They corresponded frequently and in addition to posing for photographic portraits taken by her brother, she maintained a collection of albums that he gifted to her.

The Lacock estate had been left impoverished by William Davenport but Lady Elisabeth's management restored it. She also passed her interest in languages, travel and botany on to her son. A gifted scholar, Talbot attended Harrow School and then Trinity College, Cambridge, and published six mathematical papers by 1824. In 1831, he was elected a fellow of the Royal Society.

On 20 December 1832 Talbot married Constance Mundy (1811–1880) of Markeaton in Derbyshire, ten days after his election as a Liberal MP for Chippenham. Although he did not seek re-election at the general election of December 1834, he did not retire from public life entirely, serving as High Sherriff of Wiltshire in 1840 and campaigning to protect Kew Gardens from closure in the late 1830s.

An 1833 drawing excursion to Lake Como with Constance and his half-sister Caroline was the impetus for his first experiments in photography, when Talbot found himself frustrated by his lack of skill in sketching the view. He had already tried using drawing aids such as a camera obscura and a camera lucida, and he wondered for the first time whether it would be possible to fix a reflection on paper and create a permanent image. He started experimenting in spring 1834, embedding light-sensitive silver chloride in paper and covering a portion of the paper with an oqaque object like a flower, and exposing it all to the sun. This darkened the uncovered silver chloride and left a paler, negative image of the flower on the paper. Of course, once the flower was removed, light continued to react with the silver chloride, which would destroy the negative, so he further experimented in how to wash away the silver and fix the image with salt, and also in how to create positive prints from negatives.

Setting photography aside to concentrate on, among other things, scientific work with crystals, Talbot did not return to his photographic experiments until November 1838, and almost immediately the Frenchman Louis Jacques Mandé Daguerre revealed that he had found a means of capturing images. It turned out that Daguerre used a different method to Talbot - exposing silver-plated copper rather than paper which, unlike Talbot's method, did not allow him to create multiple positive prints from a negative - but the competition led to Talbot finally submitting a paper to the Royal Society, in which he named his own technique 'photogenic drawing'. In short order, Talbot also discovered and patented a method for developing a negative chemically after only seconds or minutes exposure to light, which meant that the camera did not have to be left in the sun for up to an hour (or more) as previously. He called the resulting process 'calotype photogenic drawing', also known just as the 'calotype', or as the 'Talbotype'. Thus Talbot invented the three primary processes in photography: fixing, developing, and printing. In 1849 Horatia Feilding married Thomas Gaisford and moved to London, where in 1851 she gave birth to a son, Horace Charles Gaisford (1851-1879), and died shortly afterwards.

In 1844 Talbot began selling a serial, The Pencil of Nature which was illustrated with original photographic prints, and in 1845 Sun Pictures in Scotland, although this was marred by production problems resulting in rapidly fading images. His photographic patents also proved unpopular and were highly contested. In 1854 a court acknowledged Talbot as the inventor of photography, but ruled that his patent did not cover newer techniques like the wet collodion process, despite their evolution from the calotype. The wet collodion process, which printed on glass, produced crisper images than the calotype but like the calotype it allowed for multiple prints from a negative. As a result, it quickly overtook both calotypes and dageurreotypes in commercial use.

Partly as a result of ill health, and partly as a result of the patent strife, Talbot stopped making original photographs, but as his health improved he began to experiment again. Despite the fixing process, his silver-based images remained subject to fading, and as his own experience with publishing photographs had shown, were extremely difficult to mass produce. In 1852 Talbot patented a 'photographic engraving' process. This created an intaglio plate that could be inked up like any other printing plate, and it allowed photographs to be printed and published using long-lasting and stable printer's ink. By 1858 Talbot patented an improved process which he called 'photoglyphic engraving'. These techniques were never commercially successful in his own lifetime, but they were the origin of the modern photogravure process. Talbot kept working on photomechanical printing until he died.

Aside from photography, Talbot also did important work in translating Assyrian cuneiform and published seven books and nearly sixty scientific and mathematical articles.

He and Constance had four children, Ela Theresa (1835-1893), Rosamond Constance (1837-1906), Matilda Caroline (1839-1927) and Charles Henry (1842-1916). Only one, Matilda, ever married (to John Gilchrist-Clark, 1836-1881). The children were taught by Amélina Petit de Billier (1798-1876), a Parisian who came to Lacock originally to teach the Feildings (WHF Talbot's half sisters). Apart from a brief stint with the Hopwoods of Hopwood Hall near Manchester and a return to Paris, Petit was closely associated with the Talbot family until her death, latterly as governess and companion to Talbot's daughters, companion to Constance Talbot, and as a business agent for WHF Talbot in France. She is buried in the Lacock churchyard with the rest of the family.

Charles Henry Talbot, a historian, antiquarian and archaeologist, inherited the estate, and on his death, gave the abbey and its contents to his unmarried niece, Matilda Gilchrist-Clark (1871–1958), who changed her surname to Talbot in response. In addition to managing the estate, Matilda was, among other things, an accomplished cookery instructor who published an autobiography, My Life and Lacock Abbey, in 1956. She ensured that William Henry Fox Talbot's photographic legacy would be preserved, including distributing his photographs internationally. In 1934, she donated over 7,000 photographs to the Science Museum's chemistry collections, now in the National Science and Media Museum. In 1944 she signed Lacock Abbey over to the National Trust. The archive survived in the hands of Katharine Burnett-Brown (d. 1971), the daughter of Matilda's brother, William Gilchrist-Clark, and Katharine's children Anthony and Janet Burnett-Brown, who took over as National Trust tenants of Lacock Abbey and founded the Fox Talbot Museum in 1975.

Talbot's papers and photographs have been widely distributed over the years, mainly to public institutions, including the collection formerly on deposit at the Fox Talbot Museum, which was donated to the British Library in 2005. The Bodleian Libraries hold a core archive which was retained at Lacock Abbey, with attendant artworks and artifacts.

Adapted mainly from the Oxford Dictionary of National Biography entry on William Henry Fox Talbot.