A tree-lined avenue half a mile long studded with embassies, Kensington Palace Gardens is one of the most expensive residential streets in the world, and has long been known as "Billionaires Row", due to the huge wealth of its private residents, although in fact the majority of its current occupants are either national embassies or ambassadorial residences.

One of these was bought in 2004 by the Indian steel tycoon Lakshmi Mittal, who in 2008 was listed by Forbes magazine as the fourth richest man in the world.

The sale was widely misreported at £70 million,[2] before accurate figures were available from HM Land Registry, where records state that on 30 June 2004, 18–19 Kensington Palace Gardens, along with three mews houses at the rear of the property, sold for £57,145,967.

[3] The mansion at 18 Kensington Palace Gardens, historically belonging to the Rothschild family, was sold in 2001.

The house was demolished in 1961 and replaced by a glass-and-steel block of four apartments designed by Richard Seifert and completed in 1964.

Flat 3 was on the market in 2006 as a three-bedroom apartment designed by international architect David Chipperfield,[5] valued at a minimum of £13.25 million through Knight Frank,[6][7] which sold in March 2007 for £10.29m.

[9] Due to the presence of likely terrorist targets—embassies etc., including those of Russia and Israel—both ends of the street have armed police checkpoints (Diplomatic Protection Group officers) with crash barriers as well as the original wrought-iron gates.

This has the side effect of leading to extremely low traffic volumes for a central London street.

[11] In 1862, Edmund Ernst Leopold Schlesinger Benzon, a German-born steel magnate, moved in and lived there until his death in 1873.

[11] In 1896, the financier Leopold Hirsch had "substantial alterations" made, designed by Leonard Stokes, and he was resident until at least 1904.