However, a quick search for properties for sale at this prime address will draw blanks; the owners of these properties prefer to stay discreet for obvious reasons. Arguably the most famous address on this gilded stretch of road is Apartment 1A, Kensington Palace, the 20-room, four-storey family home of the Duke and Duchess of Cambridge.

Although it is not exactly on the same street, their garden adjoins the residences lining Billionaire's Boulevard. The estate closest to the Royal family's residence belongs to the Russian-British billionaire and owner of the Warner Music Group, Leonard Blavatnik.

In 2004 Blavatnik paid £41 million for a 13 bedroom and 9 bathroom house on Kensington Palace Gardens. After its extensive modernisation, which included construction of an impressive 25-metre swimming pool with indoor and outdoor sections, a gym, cinema, wine cellar and underground car park, it has been estimated at phenomenal £200 million making it one of the most expensive real estate in the world.

Among Blavatnik’s richest neighbours is owner of Chelsea FC Roman Abramovich and Indian steel magnate Lakshmi Mittal. In 2004 Mittal bought a home on Billionaire's Boulevard for £57 million, purchasing another property for his son four years later.

At £117 million, it was the highest price ever paid for a London house at the time. In 2013 Mittal sold the second house for £110, at a £7 million loss.

Despite the stratospheric asking prices, homeowners don't actually own the freehold to their properties. The land surrounding Kensington Palace Gardens belongs to The Crown Estate - the company that manages an extensive portfolio of land and developments owned by the reigning monarch.

As the land belongs to the Queen, all properties on Kensington Palace Gardens are sold on a leasehold basis. Leasehold is a type of ownership where one partly buys the right to occupy land or a building for a given length of time. Properties on Kensington Palace Gardens are typically sold with an excess of 100 years left on the lease, but this can be less.

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Nevertheless, owning a house on the most expensive street in the UK has its major perks. A low-profile and top security is a priority for the international super rich and Kensington Palace Gardens offers both in large quantities.

There are armed police officers at both ends of the street - Kensington Palace Gardens is also home to a number of embassies - and is fortified by a grid of CCTVs, protective bollards and stringent security clearances which keep prying eyes and the opportunistic firmly out.

So when was the last transaction? With marketing kept mostly offline and deals behind closed doors, it's hard to know exactly who is buying what and when but it was around two years ago when the last headline-hitting deal took place.

The road’s newest resident was a property tycoon from China who paid £80 million for a 10 bedroom property here -  the biggest deal to date involving a Chinese buyer in London. Joining his neighbours in collective ‘uber renovations', work is currently underway to restore the mansion which was previously home to the Nigerian High Commissioner.

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