May 6th 1840 saw the introduction of the world's first pre-paid postage stamp - the Penny Black.
The introduction of the Penny Black was a revolution in communication, the Victorian equivalent of the internet. It changed the world.
The Penny Black was an instant success with the public. Within 7 months over 160m letters had been sent, doubling the number of letters sent in the previous year.
Letters were now being sent to all corners of the globe with increased frequency.
By the turn of the century more than 2.3 billion letters had been posted.
The idea of an adhesive stamp to indicate pre-payment of postage was part of Sir Rowland Hill's 1837 proposals to reform the British postal system.
Prior to the Penny Black the cost of delivery of a letter was paid by the recipient; the price was dependent on the number of miles travelled and the size of the letter.
A two page letter sent from Scotland to London would cost the recipient two shillings, a significant investment, and £7 in today's money.
The Penny Black started a tradition that remains to this day. Look at any stamp from any country around the world and you will see the country name on the stamp. Not so British stamps. The words Great Britain do not appear.
The Penny Black had been intended for domestic use so nobody thought to add the country name.
Ask any non-philatelist what the most expensive stamp in the world is and the answer is invariably The Penny Black.
The truth is the Penny Black is not a rare stamp.
The total print run was 286,700 sheets with 68,808,000 stamps.
The majority of correspondence at the time was between legal companies who filed the letters, and many of these have survived to this day.
The Penny Black is readily available today at as little as £10 for a poor used example. Admittedly the quality won't be great.
As with all collectibles quality is a key ingredient.
A superb used example with good margins, excellent colour, and a crisp cancellation is worth approximately £250.
However, the value is in finding mint (unused) examples, of which few exist.
The original gum on a Penny Black is often said to be the most valuable substance on earth by weight.
Without it a mint Penny Black can lose up to 90% of its value. With it, untouched, as fresh as the day it was printed, it adds a significant premium to the price.
Until recently the world record for a single mint penny black was $156,000 at a Danish auction house in 2004.
However that was surpassed by British stamp dealers Stanley Gibbons who sold a single marginal example for £250,000 in 2009.
Pairs, blocks of four, and large multiples sell for significantly more.
Penny Black First Day Covers, issued on 6th May 1840, are also highly sought after.
Approximately 78 are known to exist. The most famous of all is the Kirkudbright cover that was purchased by The Royal Philatelic Collection of Her Majesty Queen Elizabeth II in 2004. The selling price is believed to have been £250,000 at the time. It is now estimated to be worth £500,000.
And of course the introduction of the Penny Black introduced a new hobby. Philately.
Famous stamp collectors have included King George V who famously spent each afternoon with his stamp collection.
On being asked over breakfast by a courtier if he had seen that some 'damned fool had paid as much as £1,400 for one stamp'. George replied "I was that damned fool."
His £1,400 had purchased the Two Pence 'Post Office' Mauritius stamp in 1904, setting a new world record in the process.
President Roosevelt was another avid stamp collector. He once quoted:
"Stamp collecting dispels boredom, enlarges our vision, broadens our knowledge, makes us better citizens and in innumerable ways, enriches our lives"
President Sarkozy, footballer Luis Figo and tennis star Maria Sharapova have all come out of the closet declaring themselves avid stamp collectors. And they're not alone.
Rare stamp expert Adrian Roose confirms that more people are believed to collect stamps than anything else on Earth.
"There are estimated to be 48 million stamp collectors in the world, with 18 million in China alone
"The interest from China is growing at a huge pace and the stamp market has already seen three new world record prices set in 2010"
Indeed the rare stamp market has opened up to a new band of investors attracted by the low volatility provided by 48m collectors underpinning prices.
One person investing in rare stamps is US Bond King Bill Gross. Mr Gross recently sold part of, including Penny Blacks, to aid the charity Dr's without Borders. After an incredible auction result Mr Gross declared:
"It's four times profit, better than the stock market"
With an ageing worldwide demographic, interest from emerging economies and a limited supply product it's not surprising that the rare stamp investment market is getting so much attention.
And none of this would have been possible without the humble penny black.
To coincide with the anniversary of the Penny Black the London 2010 Festival of Stamps opens on Saturday 8th May. This 9 day stamp extravaganza is expected to attract in the region of 50,000 stamp collectors.
You can read more about the Festival