By Sarah Begley
March 20, 2015

Twitter is celebrating its ninth anniversary on Saturday, and to commemorate the occasion, the social media site put together 10 of the most important tweets in its history.

The list acts as a potted history of the site, spanning early attempts to define the platform (co-founder Jack Dorsey’s first tweet; the first use of a hashtag), major news moments that played out on the service (Sohaib Athar’s observation of a helicopter over Abbottabad during the Osama bin Laden raid) and celebrity moments (Ellen Degeneres’s Oscar selfie, the most-retweeted tweet of all time).

Watch the timeline play out in the tweets below.

[Twitter]

Read next: Old Tweets Prove Dangerous for 2016 Campaign Staffers

Listen to the most important stories of the day.

Contact us at editors@time.com.

SPONSORED FINANCIAL CONTENT

Read More From TIME

EDIT POST