The first underground railway in the world started with the opening of the Metropolitan Railway between Bishops Road, Paddington and Farringdon on 10th January 1863.  At the Paddington end there was a connection to the GWR, which loaned locomotives and rolling stock to the Metropolitan during the first few months of operation.  Relationships between the two companies deteriorated and the Metropolitan then turned to the Great Northern Railway company for loan stock.  By July 1864, the Metropolitan could operate the service without external help, using steam locomotives with exhaust condensers built by Beyer Peacock of Manchester for tunnel working - these became the standard for both the Metropolitan and District Railways. 

After the opening of the initial section in 1863, there were various extensions to the east and the line reached Aldgate in 1876. It was further extended round to a station called Tower of London (on the site of the present Tower Hill) in 1882. A westward projection was started from a junction at Praed Street between the stations at Paddington and Edgware Road. This line passed through a new Paddington station built exclusively for the Metropolitan (the present Circle/District Line station), proceeded south to High Street Kensington and then curved east to South Kensington which was reached in 1868.

A second underground railway company then emerged - the Metropolitan District Railway, usually referred to as ‘the District’ – which built the southern section of the Circle Line between South Kensington and Mansion House, opening it in stages between 1868 and 1871.  The joint construction by the Metropolitan and District of the final link - between Mansion House and the Tower - was completed in 1884. Both companies gradually constructed extensions radiating from the Circle Line.  

All the services on the Metropolitan and District Railways were originally steam operated, but clean and quiet electric traction arrived in 1890 with the opening of the City & South London Railway. Originally designed for cable haulage, the line paved the way for future urban rapid transit systems.  The C & SLR used electric locomotives hauling trains consisting of three small carriages.  The locomotives collected direct current (dc) from an extra rail laid between the usual running rails and used the running rails to complete the circuit; improvements were gradually introduced as the technology of electric traction developed. The interiors of these early cars with their tiny windows and buttoned upholstery were so claustrophobic that they were nicknamed "padded cells" by the public.  Later, cars were much improved by the provision of proper windows and the original cars were modified to match. 

In 1900 the Central London Railway was opened between Shepherds Bush and Bank, cutting right across the central area within the Circle Line and connecting the shopping district of Oxford Street with the financial district in the City.  Electric locomotives hauled trains which were up to seven cars long.   However, after only three years of operation, the locomotives were replaced by motor cars because of excessive vibration.  Multiple unit traction then became the standard system of operation.  With a service frequency of up to 30 trains per hour, the CLR became London's first tube rapid transit railway. You can download a map of London's electric railway system, as it was in 1903, from here . 

The opening of the CLR threatened the Metropolitan Railway's traffic along the northern half of the Circle and the District's along the southern half and encouraged both railways to get together to electrify their lines.  They began with an experimental DC voltage electric service between Earls Court and High Street Kensington in 1900.  Following the experiment, they agreed between themselves to use a system of overhead electrification to be provided by the Hungarian company Ganz. Shortly afterwards, the District was taken over by the American financier Charles Yerkes who wanted to introduce track level DC supplies instead.  Eventually, after having to go to arbitration to settle the dispute, the Metropolitan and District agreed on the 630 Volt DC supply system with 3rd and 4th rails which is still in use today. A video history of the development of the London Underground system can be found here.

This is what it is like to drive a train through the dark tunnels of the Circle Line. Click on the four arrows icon to see the action in full screen mode.

Now journey on an Art Deco tube train of a similar vintage to the Brighton Belle - from Ealing Common to Uxbridge on London Underground's 1938 Tube Stock.