One of the most popular photos of the Hong Kong protests so far is that of a lone man walking through clouds of tear gas holding an open umbrella. Known as the “umbrella man,” it is drawing parallels to the “tank man,” who held up a column of Chinese tanks at Tiananmen Square 25 years ago. While it might be seen as a simple household item, the umbrella has become a curious but fitting symbol of the pro-democracy protests. Media outlets have dubbed the movement the Umbrella Revolution and the hashtag of the same name is blowing up on Twitter. Protesters are painting their umbrellas with political messages of freedom and hope.

There are a few simple reasons why: umbrellas offer shelter from rain and sun and can act as makeshift barricades. They have also been used as shields against pepper spray fired by the police. While umbrellas might generally seem like shoddy defences, they have a long history of being used as weapons: In 1838, Baron Charles Random de Berenger instructed readers of his book How to Protect Life and Property on how to use an umbrella to discreetly pull a pistol out of your pocket or whack a robber over the head. In 1978, Bulgarian secret agents used a poison-tipped umbrella to kill a dissident in London.

Umbrellas also have deep roots in Chinese society. There is evidence that parasols were invented by the ancient Egyptians, but it was the Chinese who made them waterproof with leather in the 11th century BCE. Today, they’ve become one more example of China’s unwavering economic clout, with more than 70 per cent of the world’s umbrellas produced there; and over 1,000 umbrella factories operating in the city of Shangyu alone, according to National Geographic. Observers have noted the irony of protesters adopting a symbol with such strong links to mainland China. The China Umbrella Museum, the only museum of its kind in the world, opened in Hangzhou in 2009 to display the “identity of the umbrella in the minds of Chinese people,” according to one travel website.

“Every protest needs a name, like Occupy Wall Street or the Red Shirt Army in Thailand. The umbrellas are unique because they are ubiquitous in China and have never been used like this before,” says Yongjing Zhang, professor in public and international affairs at the University of Ottawa. He says it’s fitting also because this is the first time the Hong Kong police have used such extreme tactics against protesters. The Associated Press reports that umbrellas are being donated to the movement by outside supporters to replace those being destroyed by police. With the number of protesters growing dramatically and no signs of Beijing backing down, it seems like demonstrators are going to need every umbrella they can get their hands on.