The history of the area which later became the Grosvenor Estate goes back to the time of the Norman Conquest. It was called the Manor of Eia in the Domesday book, then Eye, then Ebury. This Manor seems to have covered all the land between the Roman road (which is now Oxford Street), the Thames in the South, the Westbourne river on the West, and the Tyburn river (also known as the Eye Brook) on the east.

Geoffrey de Mandeville was granted the Manor of Eia by William the Conqueror as a reward for his services. He gave it to the Abbey of Westminster, which continued to own it until 1536 when Henry VIII broke with the Roman Catholic Church and dissolved the monasteries – and seized their property for the Crown.

Henry turned the area of Hyde into a royal park - Hyde Park. What was left was known as the Hundred Acres. James I sold the land to Sir Lionel Cranfield, an important Government official, but kept back some land which later formed part of the grounds of Buckingham Palace. He also included some additional land at Millbank. By 1626 Cranfield had fallen from favour and was being impeached for corruption.

Cranfield sold the land to Hugh Audley. He was born in 1577 and died in 1662 at the age of 85. He began his career as a law student from a humble background, but he became a successful businessman who acquired land and manors up and down the country. The manor of Ebury was probably among the least valuable of his properties, since it was little more than marshland, frequently flooded by the Thames. A few shepherds and farmers worked the land by day and thieves and cut throats worked the lanes by night.

The Grosvenor family inherited 400 acres of land between Buckingham Palace and Sloane Street, from the Thames as far north as Knightsbridge. This ultimately became Belgravia and Pimlico. In medieval times the Belgravia area was known as the Five Fields. In the 18th century it was just a wasteland used for grazing sheep. It was a dangerous place for respectable people to go. One of the bridges over the West Bourne river was called Bloody Bridge because of the number of violent robberies there. It was an area for highwaymen and footpads. It appealed to the aristocracy only as a popular area for duels, sufficiently far from civilization.

The catalyst for turning this area from a wasteland into a thriving residential district was the decision by George IV to build a new palace on the site of Buckingham House in 1819 and to move the court there.

In the 1820s Lord Grosvenor decided to develop the area as an estate to rival his existing estate in Mayfair. He came to an agreement with Thomas Cubitt. Over the next 30 years Belgravia was constructed and was immediately fashionable. Cubitt provided the estate with good quality services such as sewers and gas lighting, and well-constructed streets and pavements. Originally the area had gates and bars across the entrance of the estate to keep out undesirables and heavy traffic. The estate was named Belgravia after Belgrave, a village on the Grosvenors’ family estate in Leicestershire.

Cubitt was still only 37 when on 18th March 1825 he signed his first building agreement with Robert, 2nd Earl Grosvenor to begin construction of Belgravia. Cubitt had already performed some work for the Grosvenors in Berkeley Square. But it was still a huge gamble for both of them.

The broad outline of the ‘Five Fields’ scheme had been drafted. The fact that Cubitt had his own team of workmen and support facilities was in his favour. He was prepared to sign up for house building on a grand scale, and to provide sewers, road surfaces, and pavements. He was far-sighted enough – or reckless enough - to undertake the parallel development of the ‘Neathouse’ region, which was to become Pimlico (and was nick-named “Mr. Cubitt’s District”). Here he not only built the houses, he also built the Embankment itself and the infrastructure of sewers and roads.

Belgravia seems an obvious sure thing today. But in the 1830s it was no more than a wasteland avoided by decent folk. It was the building of Buckingham Palace, then literally on the fringes of respectable London which attracted potential buyers. Even so, it was considered so uncertain at the time whether the aristocracy would move there that when the Earl of Essex was enticed to take one of the first houses in Belgrave Square, he was nicknamed ‘the Decoy Duck’. It proved successful but it was not all plain sailing. There was a collapse in the property in the mid 1830s which Cubitt only survived by taking contract jobs from the Duke of Bedford on the Bloomsbury Estate.

Although Cubitt is generally regarded now as the builder of Belgravia, in fact his business only built 250 – 300 of the houses. Many of the terraces were assigned to smaller builders. Much of Eccleston Square and Ebury Street was built by George Watkins. W H Seth Smith built Wilton Crescent and Wilton Place. And Joseph Cundy, bother of Thomas Cundy the Grosvenors’ estate surveyor, also built in Belgravia before eventually going bankrupt.

Cubitt was one of the favourite builders of Queen Victoria and Prince Albert. The prince invited Cubitt to build the new east front of their new royal residence, Buckingham Palace. Cubitt also built ‘Osborne’, Queen Victoria’s retreat on the Isle of Wight.

In the 1850s he bought the estate of Denbies in Surrey and began building himself a house there. He died there in 1856 at the age of 68. He chose to be buried at Norwood.

This is what Queen Victoria wrote about him after his death: "In his sphere of life, with the immense business he had in hand, he is a real national loss. A better, kind-hearted or more simple, unassuming man never breathed." Thomas Cubitt was one of the few Victorian speculators to ride out all storms and die a rich man. He left more than £1,000,000 when he died – a huge sum in Victorian terms.