A "significant" Roman settlement has been uncovered outside the ancient walls of London which archaeologists say could change the story of the city.

Excavations have been under way since September at the site in Shadwell, east London, which is due to be developed into flats.

The site is the size of a football pitch and contains the remains of a palace or military headquarters only a mile east of the Tower of London.

Archaeologists say the find is significant because the evidence of development outside the Roman city has been buried under centuries of development.

The bath system indicates a high-status building

The Tower of London is considered to be Roman Londinium's eastern boundary and the remnants of the city walls can still be seen nearby.

But the status of the finds at Shadwell have surprised archaeologists and caused them to re-think the history of the period.

The settlement is thought to date from the second century because of the artefacts found.

The remains of timber framed buildings, clay and plaster walls as well as pottery, coins and hairpins were unearthed.

'Career high'

On one part of the site stone walls have been found and the remains of an underfloor heating system.

Archaeologists say the heating and the bathing system, together with a marble floor, indicate a high-status building.

Duncan Hawkins, who is leading the dig, told BBC London: "For me personally it's a career high.

"I would not expect to find a site as important as this again in my career."

Part of what is thought to b e the heating system

He said the building was demolished by the Romans after a fire and a flood damaged it.

"Water came up from a tributary of the Thames, or an inlet, and came into the building," Mr Hawkins said.

"After this disaster the Romans decided to demolish the building and rob out all these floors."

Excavations will be completed at the end of January.

The site will then be buried in sand and shingle to protect it for future generations before new flats are built on top.