British traveller and author noted for her zealous learning in a range of subjects; the Icelandic language, geology and history of art being but a few of the topics in which she was well versed. Callcott published several journals on her experiences in India, continental Europe and South America, where she also collected plants.

Lady Maria Callcott, née Dundas, was born at Papcastle near Cockermouth in Cumberland (Cumbria). Her father was a naval officer and her mother a Virginian, brought up in Liverpool. She grew up on the Isle of Man and in Cheshire, and was schooled in Oxford. After a brief appointment as a teaching assistant in Devon, she went to stay with her uncle, James Dundas, in Edinburgh, where she met the leading lights of the Scottish Enlightenment such as Dugald Stewart and John Playfair. Her sojourn mixing in this elite society was cut short by tuberculosis, which sent her into convalescence in south London over the winter of 1806-1807.

Following her recovery, the 23-year-old joined her father in 1808 on his journey by sea to Bombay, where he had been assigned head of the naval works of the British East India Company's dockyard. Continuing her enthusiastic self-education, she used the journey to learn a little Persian, read Froissart's Chronicles and teach the four youngest midshipmen. She also recorded in her journal her pleasure on tasting her first banana on the voyage. Her other great pleasure was meeting the naval lieutenant Thomas Graham, to whom she became engaged as soon as the ship docked and married a few months later at the end of 1809.

Over the next two years she travelled widely in the south and east of the country, later publishing the journal of her experiences, which covered everything from flora and wildlife to Parsi theology and illustrations of cave temples. She returned to England in 1811, living in London and Edinburgh, editing books and carrying out translation work until 1818, when she once more boarded a vessel with her husband to leave the shores of Britain, this time for Italy. After soaking up the culture in Rome and Lazio and mixing with artists including J.M.W. Turner and Charles Eastlake, they returned in 1820, in which year Callcott published a work on the life of Nicholas Poussin as well as a journal of the trip.

The couple were soon abroad again, sailing in 1821 for South America aboard a frigate under Thomas Graham's command. They arrived at Olinda, Brazil, where there was much to amaze Callcott; she was fascinated by the flora and fauna, appalled by the slave market at Bahia and shocked by the political upheaval (they had arrived during a revolution). The couple soon moved on to Rio de Janeiro and then Valparaiso, Chile. The journey to the latter was to be an unfortunate one; Thomas Graham suffered a fever and died at sea in April 1822. Despite her grief, Callcott ventured to explore her new surroundings, staying with the Scottish Lord Cochrane in Quintero. It was while she resided here that an earthquake shook the region, which she described in the Transactions of the London Geological Society. The geologist Charles Lyell used her description to support his theory that earthquakes cause land to rise; a theory criticised by George Bellas Greenough, who ridiculed Callcott's description to make his point. He was taken to task for his deed when she published a retaliatory pamphlet, and once again in 1835 when Charles Darwin, aboard the Beagle, observed the same land-forming phenomenon. Her year-long stay in Chile also resulted in many seed collections, including the bizarre Puya chilensis from the coast north of Valparaiso.

She spent most of 1823-1825 in Rio de Janeiro, where she was appointed governess to Donna Maria, daughter of the Emperor of Brazil (soon to be Queen of Portugal), and studied Brazilian history. She also prepared further journals for publication, which appeared in 1824. Back in London, she supported herself by writing articles before becoming engaged to the landscape painter Augustus Wall Callcott, whom she married in 1827. Together they took to Europe, travelling through Germany, Austria, Italy and France that year. Maria Callcott developed a passion for art at this time, due in part to the company of progressive curators and other artists encountered on the trip.

Returning to Kensington, London, Callcott busied herself with writing on history, until she was permanently invalided by a burst blood vessel in 1831. She nevertheless continued to receive distinguished visitors from the worlds of art, literature and politics, who conversed with her among her exotic plants, souvenirs of her extensive travels. Resuming her history writing, she went on to publish her most famous book, for children, Little Arthur's History of England, in 1835, and a tome on the history of painting, before turning her attentions to botany. She published three works on this subject, the last of which was her Scriptural Herbal, published in the same year that her lifelong affliction, tuberculosis, claimed her final breath (1842). Lady Callcott (her second husband was knighted in 1837) was clearly an unconventional and lively individual and is praised as a significant travel writer of the 18th century as well as making an important contribution to art criticism. Escallonia callcottiae Hook. & Arn. is named for her.