Regent Street is a major and historic shopping street located in the West End of London. It was designed by the architect John Nash and laid out between 1811 and 1825.
It was the first piece of urban planning in Britain, linking Regents Park to St. James. Effectively the two palaces of the time. Another reason was to separate the more down heel Soho from upmarket Mayfair. 
The street has a distinctive curve called “the Quadrant,” which was designed to avoid demolishing expensive properties and to keep Regent Street closer to the wealthy Mayfair area.
It was the world’s first planned shopping street and is sometimes referred to as the “Mile of Style” due to its long-standing reputation as a fashion and retail hub.
The entire street is composed of Grade II listed buildings, giving it one of the most distinguished and architecturally uniform appearances in London. Most buildings were rebuilt between 1904 and 1925 to accommodate larger commercial needs while keeping the classic Portland Stone facades.
Interesting fact…
Regent Street has spawned globally, with several other streets named “Regent Street” in cities such as Sydney, New York, and Pennsylvania