Ten years ago Tuesday, Mark Zuckerberg launched a social website called thefacebook.com from his Harvard dorm room. In the ensuing decade, the social media network now known simply as Facebook has gained 1.23 billion monthly active users and a $150 billion market capitalization. Along the way the site has added features and interfaces that define much of the way we interact online, both on Facebook and on other sites. It’s regularly courted controversy in its attempts to better serve its true customers (advertisers) by compelling users to offer up more public data. Here, we look back at ten of the most important moments in the company’s history.

Feb. 4, 2004 – Thefacebook.com Goes Live

As a sophomore at Harvard, Zuckerberg initially created a website called Facemash, which allowed students to vote on the attractiveness of their classmates. Zuckerberg was accused of hacking into school servers to access students’ photos and quickly shut the site down due to pressure Harvard administrators. Just three months later he would launch thefacebook.com, a social network that allowed Harvard students to create personal profiles that outlined their interests, along with co-founders Dustin Moskovitz, Chris Hughes and Eduardo Saveri. The direct inspiration for Facebook has been a subject of much debate for years, with a trio of Zuckerberg’s classmates claiming in a lawsuit that he stole the idea from them. Facebook eventually reached a settlement with the classmates in 2008.

October 2005 – Photo Albums Arrive

Believe it or not, the original version of Facebook didn’t allow users to create photo albums or tag friends in pictures, features that now drive much of the activity on the site. When Facebook added albums, it also included the option for users to upload an unlimited number of photos, which was unheard of among popular social networks at the time. Today Facebook users upload more than 350 million photos each day.

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April 2006 – Going Mobile

Facebook now boasts that it is a mobile-first company, but that transformation began all the way back in 2006, when the company launched its first cell phone applications through deals with Verizon, Sprint and Cingular. While mobile functionality was initially focused around posting status updates, the introduction of the iPhone in 2007 and an accompanying Facebook app in 2008 quickly transformed the way users interacted on the network. Now the majority of Facebook usage happens on mobile devices.

Sept. 5, 2006 – The News Feed Changes the Way We Share

Once upon a time, Facebook was more about updating your own profile than following what other people were doing. That changed when the company rolled out the first version of its News Feed in 2006, which pulled in info on friends’ status updates, new connections, birthdays and other data. The new feature was initially met with anger because (wait for it…) people thought it was an invasion of their privacy, but Zuckerberg defended the News Feed. Now, seeing a constant stream of your friends’ postings forms the basis of every social media site from Twitter to Instagram to Pinterest.

(PHOTOS: This Is What Your Facebook Profile Looked Like Over the Last 10 Years)

Sept. 26, 2006 – Open to Everyone

Just after Facebook launched the News Feed, it opened its doors to a much a a wider audience. Initially the site had only been for students, but in September 2006 the company decided to allow anyone above the age of 13 to join. Today it’s standard for everyone from teenagers to grandmas to have a Facebook profile. This has helped the social network reach an unprecedented scale, but it’s also driving some of its youngest users to search for online networks where they won’t be hounded by their parents.

(MORE: Now Facebook Wants to Conquer the News Game)

February 2009 – A Privacy Controversy Spurs Change

Facebook is perpetually embroiled in controversy over its privacy options (or lack thereof in some cases). Perhaps no situation got as heated as the one in February 2009, when a change to the social network’s terms of service implied that the company could hold onto users’ posts and photos forever, even after they terminated their Facebook accounts. Users were quickly up in arms, forming Facebook groups protesting the change and threatening to leave the network. Facebook called the outrage a “misunderstanding” but quickly reverted to the original terms of service. After the incident the company allowed users to vote on future changes to its terms of service and privacy policy, but that initiative ended in 2012.

October 1, 2010 – To the Silver Screen

You know you’ve become a pop culture icon when Hollywood wants to make a movie about your life. So it was with The Social Network, a retelling of Facebook’s origin starring Jessie Eisenberg as the company’s hoodie-toting CEO. The film was criticized for several glaring inaccuracies, including its overall misportrayal of Zuckerberg, (he is apparently not as much of a hothead in real life). But the movie did win several Academy Awards and grossed more than $220 million globally. The film’s success helped transform Zuckerberg into a household name.

April 9, 2012 – The Instagram Buy

In one of most high-profile tech buyouts in recent memory, Facebook agreed to scoop up the photo-sharing social network Instagram for a cool $1 billion in cash and stock in the spring of 2012. At the time, Instagram was just a year and half old and had only 13 employees. But Facebook likely saw a potential competitor in its infancy, as well as an opportunity to expand its mobile business. Since the buyout, Instagram has grown to more than 150 million users and is beginning to generate revenue for Facebook through ads. Photo messaging app Snapchat was recently offered an even more outrageous $3 billion to join the Facebook fold, but the startup declined the offer.

May 18, 2012 – Botched IPO

Hype was at a fever pitch when Facebook arrived on Wall Street in the biggest tech IPO ever in May 2012. But a series of poor decisions soured investors on Facebook for more than a year. The Nasdaq was unable to keep up with huge demand for shares, so some investors couldn’t complete transactions or were forced to buy at incorrect prices (Nasdaq was eventually fined $10 million for these blunders). Facebook also overpriced its own stock at an initial price of $38. The shares got virtually no first-day pop and tumbled to half that price in the months following the IPO on fears that Facebook would not be able to effectively monetize its mobile services.

(MORE: Actually, Facebook Is Not About to Lose 800 Million Users)

Jan. 31, 2014 – Facebook stock reaches all-time high

After more than a year of poor performance on Wall Street, Facebook finally saw its stock rebound last summer when it reported a strong surge in mobile revenue. More strong quarterly earnings reports in October and January have put the company’s stock on a steady rise for months. It closed above $62 per share on Friday, an all-time high. With big growth opportunities expected to come from Instagram and video ads this year, it’s likely that Facebook’s revenues will continue to rise.

Contact us at letters@time.com.