Use of the Golden Coach is a rare display of extravagance by the Dutch royal family. In some other countries, furious mobs opposed to rule by a hereditary monarchy seized and burnt examples of royal pomp and display long ago. But this never happened in the Netherlands, where some regard this golden coach as a symbol of national unity.

Every year on the third Tuesday in September, at the opening of parliament, this - now 112 year-old - grand horse-drawn carriage is rolled out once again. This year, Princes' Day, as this Tuesday is known, falls on 21 September.

There is a significant difference between this Dutch royal carriage and those of the former French and Russian royal houses. The House of Orange only uses the carriage on Princes' Day, for the opening of parliament. As the queen waves a royal hand and smiles, people line the streets, clapping and cheering.

Smoke bombs
Nevertheless, the golden coach is a controversial thing for many Dutch people. Extraordinarily, the coach has featured in many significant moments in recent Dutch history. It appears in many photographs taken in the turbulent 1960s. The Second World War was still fresh in many people's memories when Crown Princess Beatrix married Claus van Amsberg, a German. As the royal pair rode through the streets of Amsterdam in the carriage, smoke bombs exploded. Many photos show the golden coach, bearing the happy couple, emerging from clouds of smoke.

The story of how the coach came to be reflects much of the feeling of national unity which it has come to represent. At the end of the 19th century, Amsterdam was a highly divided city: between rich and poor, workers and bosses. Many were angry about the growing divide between the very poor and the very rich. Encouraged by a popular and persuasive preacher, people from all sides decided to donate 25 cents for a gift to mark the coronation of Queen Wilhelmina in 1898. The appeal was an overwhelming success and brought people together. The gift it paid for: the golden coach.

Royal pomp and display
Initially, Queen Wilhelmina had misgivings about accepting the gift, as she feared nationwide protests against royal pomp and extravagance. The golden coach was destined for a museum until she decided to use it for her wedding to Prince Hendrik in 1901.

On Princes' Day 2001, the world was still reeling from the September 11 attacks on New York and Washington. Many questioned whether it was wise or safe to allow the queen to use the golden coach to open parliament. However, tradition won out and it was used but the government decided something should be done to mark the terrible events of 9/11. The carriage stopped briefly in front of the US embassy in The Hague. Despite the gesture lasting a mere 15 seconds it made a deep impression; never before had a coach bearing the Dutch monarch stopped for a foreign representative to pay respects for the victims of a tragedy.

Not everyone thinks the coach is beautiful. It isn't made of gold but is just gold leaf and gold paint. The aesthetic lines of the vehicle weren't helped when the roof had to be raised in order to accommodate voluminous royal hairstyles and hats.

"Golden caravan"
When Crown-Prince Willem-Alexander was a student he had to excuse himself from lectures to attend Princes' Day. In the logbook he wrote, "I will be unable to attend tomorrow. I have to accompany my mother in a golden caravan as she rides through The Hague".

The golden coach has led a far from boring life: smoke bombs, a paint bomb during the marriage of Crown-Prince Willem-Alexander and Princess Máxima, sexual escapades by members of the Royal Constabulary and many others. Reason enough to devote 200 pages to the carriage in both Dutch and English. It's a must-have book for the hundreds of thousands of Dutch people who will line the streets on the third Tuesday of September, patiently waiting for a glimpse of the queen in the golden coach.