William Blake is a master spirit of London. He is a great Cockney visionary who saw the infinite world, the fiery world, in the streets of the capital. He understood, and helped to fashion, the symbolic presence of the city.

He divined the spiritual being of the city. Blake described it as a “human awful wonder of God”, and wandered its alleys and courtyards in a state of exultation. He left London only once but why would he need to?

As a boy (he was born the son of a haberdasher on November 28, 1757) he walked everywhere. He had so much energy that he could not help but walk. Yet he was propelled by his own sense of destiny, inescapably caught up in his experience of London.

He knew the deep and hollow roads; he knew the serpentine streets and the suffocating courts. He knew the ballad singers and the begging soldiers, the boys with trays of meat on their shoulders and the hackney-chair men.

He saw the heads of the condemned rotting on Temple Bar. He crossed the brooks and rivulets of Lambeth; he observed the mulberry trees of Peckham Rye, where he first saw angels. He knew, then, that London was blessed.

As an apprentice he lived in Great Queen Street, now off Kingsway. He lived at No 31 Great Queen Street, opposite what was then (and in altered form still is) the hall of the Freemasons. He would walk from there to Westminster Abbey, to sketch the tombs of the great dead.

He knew the people of London, too. He knew the mobs at first hand, having been taken up by one during the Gordon Riots of 1780. He was swept up at Long Acre and was hurried down Holborn towards the Old Bailey and Newgate Prison, which was burnt down and its inmates freed.

After his apprenticeship, he enrolled as a student at the Royal Academy Schools. The Academy is now off Piccadilly, but in Blake’s lifetime it was along the Strand in Somerset House. He married Catherine Boucher, a young woman from Battersea, and moved to Green Street; it has vanished but it was by the southeastern corner of Leicester Fields, now Leicester Square. Green Street was also the site of Dickens’s Old Curiosity Shop.

With another young man, Blake set up a printing business. Their premises were at No 27 Broad Street, next to the house in which he had been born and raised. At a slightly later date, he moved his printing shop only two or three streets away to No 28 Poland Street. The ground floor, where Blake set up the counter for his trade, is now a hairdressing salon.

As a young man he travelled all over London in search of employment and entertainment. He used to attend soirées at the house of a family in Rathbone Place, now Rathbone Street and attended weekly dinners at the offices of the publisher Joseph Johnson in St Paul’s Churchyard.

He also travelled to Great East Cheap, in the heart of the City, where he attended a five-day conference at the Swedenborgian chapel. Blake was one of its first adherents.

In the 1780s and 1790s, at the time of the Revolution in France, the atmosphere in London became more overtly political and polarised. There was great sympathy with the revolutionaries, and various democratic “clubs” and debating societies were instituted. Blake shared that enthusiasm.