The Gold State Coach was last used by the Queen 25 years ago for her silver jubilee.

Weighing four tons, it was first rolled out for the Queen in 1953 for her coronation.

She rode in it to the Silver Jubilee Thanksgiving Service at St Paul's Cathedral on June 7, 1977.

More recently, it was centre stage during a golden jubilee event at the Windsor Horse Show.

The coach is an 18th Century baroque work of art on wheels.

It is so heavy that it can only be pulled at a walk by eight horses, each of which has to give full effort.

Built in 1762 for George III, it has been used for every coronation since 1831 and, on occasions, for the State Opening of Parliament. It is housed in the Royal Mews at Buckingham Palace.

As its name implies, the ornate coach is gilded all over. The exterior is also decorated with painted panels by the Florentine artist and engraver Giovanni Battista Cipriani, who was working in London in the 1760s.

The interior is lined with crimson velvet and satin.

The coach is decorated with symbols of Britain's victory in the Seven Years' War (1756 to 1763).

The body of the coach is slung by leather-covered braces, ornamented with gilt buckles held by four Tritons - sea gods with a man's head and a fish's tail.

The two rear Tritons carry the fasces, crowned with tridents, the symbols of imperial power.

The roof is ornamented with three cherubs, representing England, Scotland and Ireland, supporting the royal crown and holding the sceptre, sword of state and ensign of knighthood.

The driver's footboard, no longer used but still in place, is in the shape of a scallop shell and is ornamented with bunches of reeds.

Measuring 24ft long, 8ft wide and 12ft high, the coach was originally driven from above the footboard, but Edward VII had the driver's box removed so spectators could get a better view of the passengers.

The coach is now drawn by eight greys, four mounted by postilion riders.

Head coachman Colin Henderson, who walks alongside the coach directing the team, said: ''The carriage is on leather braces and not only rocks backwards and forwards but also oscillates, so I don't think it can be a particularly comfortable or enjoyable ride.''