In March 1928 British Electric Traction, a company that had started life supplying cabling systems for electric trams in the 19th century, formed Broadcast Relay Service Ltd. Using their pre-existing cabling systems, the company used its distribution network to carry radio broadcasts by wire into homes, avoiding the need for complex and hard-to-operate early radio sets.

BRSL soon became known as 'Rediffusion' - a name meaning simply 'broadcasting again'. With the advent of the BBC Television Service in 1936, Rediffusion was well placed to rent TV receivers and to provide a basic form of cable TV service to subscribers.

After the war, BET and Rediffusion diversified into providing wired distribution and ultimately wireless broadcasting, including commercial radio, in the former and remaining British Colonies. With the announcement of commercial television in the UK, Rediffusion was quickly on the scene with a bid. BET brought in a partner in the form of Associated Newspapers, owners of the Daily Mail with a 50% stake.

The first contracts were awarded on October 26, 1954, just three months after the Independent Television Association had been formed, and the new company, Associated Rediffusion, was given the franchise for Monday to Friday in the London area. With only 11 months to get on the air, Associated Rediffusion installed itself in the former RAF headquarters on Kingsway. In charge of operations at Kingsway was A-R's General Manager, Captain Tom Brownrigg. The Kingsway building housed four small continuity and news studios, but the main production facility was a five-studio complex at Wembley, originally the British home of 20th Century Fox.

Following a series of test transmissions, commercial television in the UK began on Thursday, 22 September 1955, with an evening jointly programmed by A-R and 'ABC', Lew Grade's consortium that held the London weekend contract and was soon to become known as ATV after a disagreement with ABPC. The opening night included a live feed from the opening ceremony in the Guildhall, a variety performance and the first commercial on British television, an ad for Gibb's SR toothpaste at ten past eight, for which Elida Gibbs paid 50% over ratecard (the scale of standard charges for buying broadcast advertising time). Drama, a boxing match, Chris Chataway reading the news from ITN and live coverage of the opening night party took the evening up to a closedown prayer at 11:05pm.

There was only one problem: the evening had made a dramatic financial loss. With just two companies responsible for all the programming for several months after the opening, income continued to lag behind costs, and, by the first anniversary, Associated Rediffusion had lost £3 Million. Associated Newspapers wanted to back out, and Rediffusion bought 80% of its shares. But with the major players in the network by now in place, 1959 saw A-R's annual profits reach £2.7 million. By the end of ITV's first decade they were twice that of the entire Rediffusion operation in 1955.

The 1964 franchise round saw no changes in the fortunes of existing ITV companies. However, Associated Newspapers finally withdrew completely from A-R as a requirement to maintain a one-third stake in Southern Television. The 'Associated' was thus dropped from the name, and the station relaunched itself as 'Rediffusion, London's Television'. The station remained profitable for another four years.

When it came to the 1968 renewal process, however, things were different. Charles Hill, who had been present at the opening of ITV a dozen years earlier as head of the ITA, had been considering obliging applicants to merge - an idea not without precedent - as a way of allowing new blood into the network. He proposed that ABC Television, weekend contractors in the Midlands and the North, and Rediffusion should set up a joint company in which ABC, upon whom the regulator looked favourably, would own 51%, and thus have control. Rediffusion was able to negotiate an equal split of profits, but not equal power. As a result, the new company formed by the parent company of each, to be called Thames Television, was to owe a great deal more to the style of ABC than it did to Rediffusion, and as a television company, Rediffusion disappeared from London's screens on 29 July 1968.