September 1998

September 1998
Larry Page and Sergey Brin incorporate Google and set up a workspace in Susan Wojcicki's garage in Menlo Park, California.

April 1999

April 1999
Co-founders Page and Brin hire Wojcicki, employee No. 16.

June 1999

June 1999
Marissa Mayer joins Google straight out of Stanford grad school. She is employee No. 20 and Google's first female engineer.

November 2001

November 2001
New CEO Eric Schmidt recruits Sheryl Sandberg to move to Google from ­Washington, D.C., where she was chief of staff to U.S. Treasury Secretary Larry Summers.

June 2003

June 2003
Megan Smith joins Google after heading PlanetOut, the first venture-backed LGBT online community site.

August 2004

August 2004
Google goes public at $85 a share, raising $1.9 billion.

October 2006

October 2006
Google buys YouTube for $1.6 billion—after ad boss Wojcicki advocates for the deal, as YouTube is ­eclipsing Google Video.

April 2007

April 2007
Google announces the acquisition of online ad giant DoubleClick for $3.1 billion.

March 2008

March 2008
Sandberg, Google's VP of online sales and operations, quits to become COO of Facebook and No. 2 to CEO Mark Zuckerberg.

September 2011

September 2011
Mayer, VP of Google Maps and location services, leads Google's acquisition of restaurant finder Zagat for $151 million.

May 2012

May 2012
Google acquires Motorola Mobility for $12.5 billion to fortify Android, its mobile operating system.

July 2012

July 2012
Mayer leaves Google to become CEO of Yahoo. (She discloses to Fortune exclusively: "I'm pregnant.")

February 2014

February 2014
Google acquires Nest Labs, a maker of home-automation products, for $3.2 billion.

September 2014

September 2014
Megan Smith, VP of Google X, answers a call from President Obama and becomes the first U.S. chief technology officer.

May 2015

May 2015
Ruth Porat, Morgan Stanley's former finance chief, moves to Google as its new CFO.

July 2015

July 2015
Porat leads her first earnings call; Google gains $65 billion in market value in one day.

August 2015

August 2015
Google announces a new corporate structure and introduces Alphabet, its new holding company.