The skin is about to be ripped back from one of the most foetid slums in Britain, a London parish which became such a byword for filth and squalor that the phrase “a St Giles cellar” literally signified the lowest depth of abject poverty.

A unique collaboration of archaeology by the Museum of London, and historical research and new paintings by the artist Jane Palm-Gold, will reveal the lives of the thousands of people who once lived crammed into the Rookery, a warren of semi-derelict homes, alleys and courtyards where Renzo Piano’s huge multi-coloured office and residential blocks now rise behind Centre Point in the West End.

The archaeological finds, to be displayed for the first time in the exhibition as the excavators launch their report on the site, chart the startling decline from 17th-century affluence to Georgian squalor, as the old houses were subdivided and let out as common lodgings – with so many Irish Catholic residents, it was dubbed “Little Dublin” or “the Holy Land”.

Luxury imported china and glass, and charming objects such as the fuddling-cup, a puzzle vessel for tavern drinking games, gave way to the cheapest and poorest: 19th-century finds include chamber pots, clay pipes, gaming tokens, cheap flashy jewellery probably worn by prostitutes, and a baby’s feeding bottle which may often have held gin, when one in four premises was a gin shop – and far fewer possessions of any kind than are found in comparable sites.

One excavated cellar is believed to have been home to many families, and had an open sewer running across the floor. Another massive cesspit provided many of the finds.

Sian Anthony, who led the dig, found evidence backing residents’ complaints that landlords frequently boarded pits over and left them full, rather than pay for them to be cleaned out.

An 1847 medical report described the area as “a disgrace to a civilised country,” and in 1849 some residents actually wrote to the Times: “We live in muck and filth. We aint got no priviz, no dust bins, no drains, no water-splies, and no drain or suer in the hole place.”

One outsider recorded in 1852 – when the area had slightly improved: “In a back alley opening onto Church Street was a den which looked more like a cow-house than a room for human beings – little if any light came through and yet 17 human beings ate drank and slept there; the floor was damp and below the level of the court; the gutters overflowed; when it rained, the rain gushed in at the apertures.”

The archaeologists also found one of the infamous secret passages, which meant the police – if they dared venture in – found it almost impossible to catch criminals, who could escape through a maze of escape routes through, over and under buildings.

Palm-Gold’s paintings, inspired by historic prints including William Hogarth’s Gin Lane, track the contemporary wild side of the area where she lives. She personally witnessed all the depicted incidents from the windows or balcony of her flat in her panorama Crack Lane. They include the crack dealer who broke open and moved into the bin store of her own buildings, two men found dead in the community Phoenix Gardens, a couple having sex by the churchyard steps, a punter attacked by two prostitutes joined by two crack dealers, and a drug user smashing open letter boxes to steal not the contents of the envelopes but the identities, a flourishing local trade.

On another occasion she saw police hunting through bushes, looking for drugs. When they finally gave up, she watched two men ripping back a grating covering the opening to the church crypt to recover the drugs they had thrown in.

It all repelled and fascinated her predecessors – Hogarth, Thomas Rowlandson and Gustav Dore were among the artists drawn to the area. As she pored through hundreds of prints in the British Museum and other archives, she came to recognise characters drawn by many artists, who reappear as ghostly figures in her own pictures: Billy Waters, king of the beggars; Old Simon Edy with his flowing hair and beard who lived under a broken staircase in Dyott Street; blind Charlie Wood with his dancing dog, Bob.

She moved to the heart of the area in 2003 – the road past her door was once the dirt track to a huge leper hospital – and absolutely loved it. “It is completely wild, and some of the things I have seen you would just not believe, but I have never had better neighbours anywhere. They’ll carry me out of here in a box.”

* London’s Underworld Unearthed: the Secret Life of the Rookery, Coningsby Gallery London, 17 May-3 June