Ashmole supported the royalist side during the English Civil War, and at the restoration of Charles II he was rewarded with several lucrative offices.

[1] His library reflected his intellectual outlook, including works on English history, law, numismatics, chorography, alchemy, astrology, astronomy and botany.

Although he was one of the founding Fellows of the Royal Society, a key institution in the development of experimental science, his interests were antiquarian and mystical as well as scientific.

He enjoyed a successful legal practice in London, and married Eleanor Mainwaring (1603–1641), a member of a déclassé Cheshire aristocratic family, who died while pregnant[5] only three years later on 6 December 1641.

He also became allied with Major-General Charles Worsley (who died 12 June 1656 and was buried at Westminster Abbey), brother-in-law of his sister, Mary Ashmole, who married John Booth of Salford.

[6] Soon afterwards, at the suggestion of George Wharton, a leading astrologer with strong court connections, Ashmole was given a military post at Oxford, where he served as an ordnance officer for the King's forces.

He was given the additional military post of captain in Lord Astley's Regiment of Foot, part of the Royalist Infantry, though as a mathematician, he was seconded to artillery positions.

His diary entry for 16 October 1646 reads in part: "I was made a Free Mason at Warrington in Lancashire, with Coll: Henry Mainwaring of Karincham [Kermincham] in Cheshire.

I was the Senior Fellow among them (it being 35 yeares since I was admitted) ... We all dyned at the halfe Moone Taverne in Cheapeside, at a Noble Dinner prepaired at the charge of the New-accepted Masons.

[15] In 1649, he married Mary, Lady Mainwaring (daughter of Sir William Forster of Aldermaston), a wealthy thrice-widowed woman twenty years his senior;[16] she may have been a relative by marriage of his first wife's family and was the mother of grown children.

The marriage took place despite the opposition of the bride's family, and it did not prove to be harmonious: Lady Mainwaring filed suit for separation and alimony but it was dismissed by the courts in 1657.

Nevertheless, the marriage provided Ashmole with Mary's first husband's estates centred on Bradfield in Berkshire which left him wealthy enough to pursue his interests, including botany and alchemy, without concern for having to earn a living.

In 1652, he published his most important alchemical work, Theatrum Chemicum Britannicum, an extensively annotated compilation of metaphysical poems in English.

Tradescant had, with his father, built up a vast and renowned collection of exotic plants, mineral specimens and other curiosities from around the world at their house in Lambeth.

When Tradescant died in 1662, his widow, Hester, contested the deed, claiming her husband had signed it when drunk without knowing its contents, but the matter was settled in Chancery in Ashmole's favour two years later.

[21][22] Ashmole embarked on further catalogues, including one of the Roman coin collection of the Bodleian Library, which he finally completed in 1666 after eight years of work.

In this position he devoted himself to the study of the history of the Order of the Garter, which had been a special interest of his since the 1650s, and he proposed a design for the Royal Society's coat of arms.

[14] By 1665, he was collecting information for his county history, The Antiquities of Berkshire; and in 1672 he published The Institution, Laws and Ceremonies of the Most Noble Order of the Garter, a lavish folio with illustrations by Wenceslaus Hollar, for which he had conducted years of research.

Ashmole performed the heraldic and genealogical work of his office scrupulously, and he was considered a leading authority on court protocol and ceremony.

After the Restoration, Ashmole was granted a new crest in place of the greyhound, one which reflected his interest in astrology: On a wreath Sable and Or the Planet Mercury collocated in the middle of the caelestiall Signe Gemini Proper his right hand extended toward Heaven and left holding a caducan Rod Or.

In 1684, Dugdale wrote to his son-in-law that "the vulgar sort of people" were not "yet weaned from the presbyterian practises, which was long prayers of their own devising, and senseless sermons".

However, the notion of a repository of universal knowledge is described in Rosicrucian writings and this idea may have partly inspired Ashmole's desire to found a great museum.

It would have been more, but a large part of Ashmole's own collection, destined for the museum, including antiquities, books, manuscripts, prints, and 9,000 coins and medals, was destroyed in a disastrous fire in the Middle Temple on 26 January 1679.

Surviving documents indicate that he was the most popular candidate, but after King James II requested he stand down (in an age when monarchs were likely to interfere with parliamentary elections), Ashmole did so.