Until King Charles I’s 1635 decree made England’s Royal Mail public, the service was available only to the royal family and high-ranking officials. (Alan Holyoake)

The next time you find yourself at the post office, thank (or blame) Charles I of England.

Although the monarch was somewhat of a selfish tyrant, before his spats with Parliament led to the English Civil War in 1642, he signed a decree that opened up the Royal Mail for public use, making it the world’s first public mail service. That decree, together with examples of the first postage stamp and prepaid envelope, will be on display starting Friday at the National Postal Museum.

“Charles I had an altercation with Parliament over funding his expensive wars — today we’d call it gridlock,” says Daniel Piazza, curator of the “From Royal Mail to Public Post” exhibit. “He had to think of new ways to make money other than taxation.” He came up with the idea of widening the Royal Mail, which had only served the royal family and high-ranking public officials. In 1635, when the decree was signed, “most of the demand was coming from merchants,” Piazza says, pointing out that a majority of the British population was either illiterate or had no need for such a service, with generations of families living and dying in the same small villages and towns. But all that would change with the Industrial Revolution.

“By 1840, literacy was greater and there was more demand among individuals to use mail as more people moved to the city,” Piazza says. By that time, the postal system was running a deficit, largely due to the fact that the recipient paid postage, and many people were rejecting letters. “It was not a sustainable business model,” Piazza says. “The very idea of charging for postage in advance comes from this moment.”

In need of some sort of proof that the sender had paid, the Royal Mail introduced two methods in 1840, each costing a single penny: postage stamps and prepaid envelopes. The first stamp featured a profile of 15-year-old Queen Victoria, while the envelopes were decorated with busy, heroic scenes, which many people thought made them “too pretentious,” Piazza says.

So why are these British historical artifacts, on loan from a private collector in the U.K., on display at the United States’ National Postal Museum?

“The reform of the mail was seen as a tool to all other social reforms,” enabling proponents for women’s suffrage, temperance and vegetarianism to spread their messages, Piazza says. “Anti-slavery in the U.S. was tied to the cheap postage movement. The postal service is a democratizing institution and the only other essentially Victorian technology we still use besides railroads.”

National Postal Museum, 2 Massachusetts Ave. NE; Fri. through Jan. 16, free.

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