BBC sitcom Only Fools and Horses celebrated its 21st birthday on Sunday with the transmission of the original episode of the series.

The first ever outing of the Trotter family, starring David Jason, Nicholas Lyndhurst and Lennard Pearce, drew nine million viewers and the series went on to become one of the institutions of British comedy.

After 20 years the Trotters finally found their fortune

It made household names of the stars and introduced phrases such as "Rodney, you plonker", "he who dares" and "luvvly jubbly" to the British vocabulary.

The series greatest success was drawing 24 million viewers to its Christmas episode in 2001, in which the Trotter family finally finds wealth.

'Millionaires'

While writer John Sullivan's comedy has featured a variety of supporting characters and plotlines, the basis of the series has changed little.

It features Derek "Del Boy" Trotter (Jason), a loveable rogue with one eye on the next opportunity and always hoping that "next year we'll be millionaires".

In the first episode, market trader Del buys a consignment of briefcases which he thinks he can sell to city traders.

Unfortunately, all the cases are faulty and do not open.

Meanwhile his younger brother Rodney (Lyndhurst) is thinking of giving up trading to pursue a "real" job.

While not an instant hit with the viewers, many complained they did not understand the title, a second series was commissioned and it went on to become a landmark programme for the BBC.

John Sullivan's self-penned and sung theme tune, one of the trademarks of the show, was introduced during the second series to help explain the title.

Original tune

Sullivan sings "but why do only fools and horses work?" in the theme.

When the original show, called Big Brother, is re-broadcast on 8 September it will feature the original tune.

Two final episodes of the comedy were filmed in 2002 and are due to be shown later this year.