Īlthough of even older origin, the company was incorporated under a Royal Charter in 1394, the company's earliest extant Charter.

Serlo le Mercer (who was Mayor of London for five terms in the early 1210s) was a member of the company and was one of the negotiators of Magna Carta. Magna Carta was negotiated by a member of the Mercers In 1210-1214, the first two Mayors of London, Henry FitzAlwyn and Robert FitzAlwyn were claimed to be members, and branch of the company was established at this time, the Company of Merchant Adventurers, who established themselves at Antwerp, the centre of the cloth trade. Its corporate existence began in the form of a fraternity at least by the reign of King Henry II, in the mid 1100s if not before. The city block upon which it stands contains the archaeology of a Roman-British temple known today as Gresham Temple. The Mercers' Company is based at Mercers' Hall, 6 Frederick's Place in the City of London. 1100–1150) was probably the portreeve of London History Henry fitz Ailwin, thought a Mercer, was 1st Lord Mayor of London of mainly English rather than Norman descent, his grandfather Leofstan (c. The company's motto is Honor Deo, Latin for 'Honour to God'. Today, the Company exists primarily as a charitable institution, supporting a variety of causes. It is the first of the Great Twelve City Livery Companies. The Worshipful Company of Mercers is the premier livery company of the City of London and ranks first in the order of precedence of the Companies. Mercers' Hall, 6 Frederick's Place, City of London

Geni haberdashers guild project