The excavation in Edinburgh has lasted more than a year, three times longer than expected, due to the range of objects and material discovered from the 10th century.
Experts say the remains of buildings found predate Edinburgh Castle and the creation of the town burgh by David I by around 200 years.
The work has also unearthed ditches and walls marking the original boundary of the city and some of the discoveries could date as far back as the Bronze Age.
The findings are expected to become a major selling point of a stay in Sir Richard’s first hotel in the UK, which will boast 225 rooms and create more than 300 jobs.
During a 60 week excavation a human skull, a drinking vessel, shoes, jewellery, and knives, along with a ball used in a giant catapult and an early cannonball were discovered at the Cowgate site.
Hearths, wall panel, structural timbers, rubbish pits and wells have been unearthed during the dig, which took around three times longer than initially anticipated by the Virgin team working on the project.
The plans for the hotel at the India Buildings on Victoria Street and an adjacent gap site were announced in February of last year, with a 2020 opening date.
But Virgin Hotels said work would finally begin at the site “within weeks,” with the aim of the hotel now opening in 2021.
Edinburgh City Council archaeologist, John Lawson said: “This has been one of the most significant urban excavations ever undertaken in Scotland.
“We have found everything we could have probably hoped to find on an excavation like this – there was basically 1,000 years of archaeology on the site.
“The full analysis and research has still to be done, but the results of the work have been tremendous, in terms of scale and quality, and the quality of preservation is outstanding.
“For the first time ever, we have found a series of buildings which pre-date the formation of the medieval town in the 12th century.
“There are a great sequence of layers on the site which almost tell the story of Edinburgh in microcosm.”
Raul Leal, chief executive of Virgin Hotels, said: “We always knew India Buildings was a special place and a very special development, though I’m not sure we could have guessed just how amazing it really is.
“A unique insight has been gained into life in Edinburgh and the city’s development over nearly 1,000 years.
“We will look at ways we can inform our guests of the rich history beneath the rooms in which they sleep.”
The building of the new hotel close to Edinburgh’s historic Grassmarket has proven highly controversial, and has been met with criticism from a heritage watchdog and high-profile protests, led by a group called Let There Be Light.
In May 2018, 19 notable writers, artists and academics wrote a letter to The Times, denouncing the enterprise as “asset stripping”.
Register for free to continue reading
Registration is a free and easy way to support our truly independent journalism
By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists
Already have an account? sign in
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies