They took Google from a Silicon Valley start-up to one of the most powerful companies in the world - and now, they're stepping down.
Larry Page and Sergey Brin - who co-founded Google 21 years ago - announced Tuesday they're leaving their respective roles as CEO and President of parent company Alphabet, effective immediately.
Replacing Page as Alphabet's CEO - Sundar Pichai, the current chief executive of Google, who will retain that title.
Pichai's expanded duties as head of Alphabet include overseeing self-driving car technology company Waymo, healthcare software firm Verily and several other businesses.
Brin's role as President of Alphabet will not be filled, the company said.
Brin and Page explained in a blogpost that it's "the natural time to simplify our management structure."
And adding, "...we believe it's time to assume the role of proud parents - offering advice and love, but not daily nagging!"
The two - who had once been regular sights at public events and at Google headquarters - had retreated into the background recently.
Page in particular, as CEO, sometimes drew criticism from employees and lawmakers demanding answers from him - rather than Pichai.
The two said they will remain actively involved as board members.
In closing, Page and Brin noted how Google started as a "small research project" while they were students at Stanford, writing, "We could not have imagined, back in 1998 when we moved our servers from a dorm room to a garage, the journey that would follow."