The #hashtag turns 11

Twitter is celebrating 11 years since it first introduced the world to the hashtag. On this day in 2007, Twitter user @chrismessina used a hashtag on Twitter for the first time.

how do you feel about using # (pound) for groups. As in #barcamp [msg]?

— Chris Messina™ (@chrismessina) August 23, 2007

Since then, the hashtag has evolved from a user-created way to categorise or 'tag' Tweets, to become part of our everyday speech, changing the nature of communication online, and becoming one of the most influential symbols of the digital age.