The Economic Times

The # symbol you see under every Instagram post was once just a Roman weight measurement. It took centuries to become social media's hashtag

The familiar # symbol is something most people now associate with social media, trending topics and Instagram posts, but its story is far older than the internet. The mark has passed through several different uses and names over the centuries, picking up new meanings as technology and communication changed. Its long journey includes an unexpected connection to the ancient world and some familiar names from the history of writing and technology.