The Proof House: 48-50 Commercial Road, London E1 1LP
Worshipful Company of Gunmakers
Telephone: +44 (0) 20 7481 2695
The Worshipful Company of Gunmakers was incorporated by Royal Charter in 1637 to promote and regulate gunmaking, a role it still fulfils today.
Governed by the Master, Wardens and Court of Assistants. Activities encompass four broad areas of operation: Regulatory, Charitable, Social and Civic.

The Livery

The Worshipful Company of Gunmakers is governed by the Master, Wardens and Court of Assistants. Its activities encompass four broad areas of operation: regulatory, charitable, social and civic.

The Worshipful Company of Gunmakers was founded in 1637, after decades of argument over which City Company would regulate the emerging trade of gunmaking. The first recorded use of gunpowder and cannon by an English army was at Crecy in 1346, as a sort of curtain raiser for the longbows. However, guns were not seen as an essential element of warfare until the defeat of the Spanish armada in 1588. Sound cannon and good tactics enabled the small and swift British fleet to cut a swathe through the lumbering Spaniards. After that, the supply of guns became a matter of national importance.

In 1589, a group of gunmakers drew up draft procedures for proving the safety of firearms. But their efforts to form a new Company for the regulation of this emerging trade immediately ran into opposition from existing Companies, notably the Blacksmiths and the Armourers. After a generation of squabbling, a Royal Commission was created in 1631. On its recommendation, an independent Gunmakers’ Company was granted a Royal Charter by Charles I on 14 March 1637 – although even then further bureaucratic opposition, plus the outbreak of civil war, delayed enforcement of that Charter until 1656.

The Charter defined the role that the Gunmakers still play today. It created a proof mark, a stamp of the letters ‘GP’ surmounted by a crown. The mark is stamped on guns that meet the statutory safety requirements. Only the Company can bestow it, and it is illegal to sell a gun without a recognised proof mark. To administer proof, the Company was given broad powers of “search, gage, proof, trial and marking of all manner of hand guns in London or … imported from foreign parts”.  The power to search (with a constable) for unproved guns and seize them is still vested in the Company today.

The Company is unique in having always had its premises outside the City walls, possibly due to the noise and nuisance of its early (and now superceded) proof procedures. It established its first proof house in 1657 underneath a bulwark near Aldgate. By the 1670s, the walls, bulwark and proof house were crumbling, so in 1675 the Company secured some land in a physic garden at Whitechapel, on what is now the Commercial Road. There, it built a small compound which included the proof house, where the actual work of testing barrels was done, the livery hall and, in earlier centuries at least, housing for the Proof Master. The livery hall at No.46 Commercial Road was sold in the 1920s, when the Company thought it superfluous to requirements, but it was repurchased in 2007.

The gun trade grew strongly over the course of the 17th and 18th centuries. Many of the new companies were located in Birmingham, to take advantage of local expertise in metalworking and engineering. So in 1813, an Act of Parliament authorised creation of the Birmingham Gun Barrel Proof House. The two proof houses now divide the work of gun proof in Britain between them, and cooperate internationally through membership of the Commission Internationale Permanente pour l’Epreuve des Armes à Feu Portatives (CIP).

Another important aspect of the Company’s business is the award of Gunmakers’ Certification to gunmakers’ apprentices once they have completed their training. The award marks the point at which an individual can start to work unsupervised in one or more of the crafts of gunmaking. 

The Gunmakers are proud to remain a working company, one of the few City of London Livery Companies who still carry out the work for which they were founded. Although the Company maintains strong links with the British gun trade, its members encompass a broad range of professions. Together with the rest of the Livery movement, the Company supports the Lord Mayor of the City of London and engages in social and charitable activities. The Gunmakers’ Company Charitable Trust helps support training and innovation in gunmaking.

Gunmakers’ Company Charter & Ordinances


Since 1675, the Worshipful Company of Gunmakers has been located at its present location, just outside Aldgate and the old walls of the City of London. For directions visit our Contact page.


The Company operates the Proof House, which has statutory powers to test and regulate the safety of firearms.


Members of the Livery serve as trustees of the Gunmakers Company Charitable Trust, which provides assistance for training gunmakers and advancement of the art and technology of gunmaking and related trades.


The Company organises formal dinners and other activities and events for its liverymen (which includes women).


The Livery participates in the governance of the City of London, including the election of the Sheriffs and the Lord Mayor.


No gun can be legally sold in the United Kingdom without having undergone proof.


The Proof House is called in to investigate accidents caused by firearms malfunction.


The Proof House ensures and certifies that guns wanted for display purposes, rather than use, have been made permanently unusable in the manner required by law.