Allegory: noun - a narrative written under the guise of another and sharing points of correspondence with it; symbolic representation; an extended metaphor; an emblem; a picture where meaning is represented symbolically.
Allegory in the visual arts is almost as old as the art form itself. I could list hundreds of examples, but will make do with just three representatives of the form: Sandro Botticelli' s Primavera, also known as Allegory of Spring, Johann Vermeer's Allegory of the Catholic Faith and Il Bronzino's Venus, Cupid, Folly and Time
In literature, there is the famous case of the 'mistaken' allegory as exemplified by JRR Tolkien's Lord of the Rings, which many critics assumed to be an allegory of WWII, in spite of Tolkien's emphatic denial of such and his assertion that he loathed the very idea of allegory.
Amongst those works that are recognised as allegory, of which there are many, a few are as follows:
Jonathan Swift's political allegory, Gulliver's Travels, William Golding's Lord of the Flies, an allegory about the conflicting forces that apply to civilisation and power, and, of course, the famously allegorical work by George Orwell. In Animal Farm the author skilfully caricatures the rise of Stalin and the follies of the communist state.
Many works of fiction contain elements of allegory and some have said that my own Breaking Faith is an allegory of good and evil. I'd argue that 'good and evil' is too wide a topic to be the subject of allegory and, in any case, is more a theme than a subject for allegory. But it is nevertheless true that many novels that are not specifically allegorical do carry an element or elements of allegory within them. Often, however, these are interpretations made by readers and critics, rather than intentional designs of the authors.
1696 - A window tax was imposed in England, causing many shopkeepers to brick up their windows to avoid the tax. It was repealed on the 24th July 1851, following much lobbying. A similar tax was imposed in France from 1798 and lasted until 1926. A real example of the wealthy law-makers being oblivious to the harm caused by thoughtless legislation on those less well-off, it was responsible for serious deterioration in living conditions for many of those who lived in poverty. The lack of light and air caused innumerable illnesses and deaths amongst the poor. Walking around England's historical urban areas it is easy to mistake some architectural devices for examples of attempts to defeat the window tax. Many windows were, or course, bricked up as a result of the imposition, but the habit of designing 'mock' windows continued long after the tax had been repealed and goes on today, with the decorative elements now used to harmonise and bring symmetry into the design of some buildings.