Imperial staircase

[2] The Jordan Staircase of the Winter Palace is a notable example, while other such staircases can be found at Buckingham Palace, Windsor Castle, Palazzo Reale di Caserta, Palacio Real de Madrid and Mentmore Towers.

The advantages of an imperial staircase became apparent during the 18th century, when Matthew Brettingham revolutionised the design of the piano nobile of the London town house.

[3] At large gatherings the two branches could ease the flow of guests arriving and departing, or moving between a ballroom and a supper room on the floor below.

An imperial staircase is often used today for similar reasons where two streams of people are moving in opposite directions in buildings as diverse as an opera house to a railway station.

Occasionally, especially in the architecture of the Sicilian Baroque, they will leave the ground as one flight and then divide, but this is less common.