Blue plaque

A blue plaque is a permanent sign installed in a public place in the United Kingdom, and certain other countries and territories, to commemorate a link between that location and a famous person, event, or former building on the site, serving as a historical marker.

The term is used in the United Kingdom in two senses. It may be used narrowly and specifically to refer to the "official" scheme administered by English Heritage, and for much of its history restricted to sites within Greater London; or it may be used less formally to encompass a number of similar schemes administered by organisations throughout the UK. The plaques erected are made in a variety of designs, shapes, materials and colours: some are blue, others are not. However, the term "blue plaque" is often used informally to encompass all such schemes.

The "official" scheme traces its origins to that launched in 1866 in London, on the initiative of the politician William Ewart, to mark the homes and workplaces of famous people. The first such scheme in the world, it has provided inspiration and model for many others. The scheme has been administered successively by the Society of Arts (1866–1901), the London County Council (1901–1965), the Greater London Council (1965–1986) and English Heritage (1986 to date). It was initially focused on Greater London, although between 1998 and 2005, under a trial programme since discontinued, 34 plaques were erected elsewhere in England. The Levelling-up and Regeneration Act 2023 extended the scheme to the whole of England though the plaques since erected outside of London have been put up by Historic England rather than English Heritage.

Many other plaque schemes have been initiated in the United Kingdom. Some are restricted to a geographical area, others to a particular theme of historical commemoration. They are administered by a range of bodies including local authorities, civic societies, residents' associations and other organisations such as the Transport Trust, the Royal Society of Chemistry, the Music Hall Guild of Great Britain and America and the British Comic Society.

There are commemorative plaque schemes throughout the world such as those in Paris, Rome, Oslo, and Dublin and in cities in Australia, Canada, the Philippines, Russia, and the United States. These take various forms and they are more likely to be known as commemorative plaques or historical markers.

The original blue plaque scheme was established by the Society of Arts in 1867, and since 1986 has been run by English Heritage. It is the oldest such scheme in the world.

After being conceived by politician William Ewart in 1863, the scheme was initiated in 1866 by Ewart, Henry Cole and the Society of Arts (now the Royal Society of Arts), which erected plaques in a variety of shapes and colours.

The first plaque was unveiled in 1867 to commemorate Lord Byron at his birthplace, 24 Holles Street, Cavendish Square. This house was demolished in 1889. The earliest blue plaque to survive, also put up in 1867, commemorates Napoleon III in King Street, St James's. Byron's plaque was blue, but the colour was changed by the manufacturer Minton, Hollins & Co to chocolate brown to save money. The first woman to be honoured with a plaque was the actor Sarah Siddons in 1876. The plaque, placed on her house in Marylebone, London, was retrieved when the house was demolished in 1905 and is now held in the Victoria and Albert Museum.