(CNN)Here is a look at the life of Bill Gates, co-founder of Microsoft Corporation.
Birth date: October 28, 1955
Birth place: Seattle, Washington
Birth name: William Henry Gates III
Father: William Henry Gates II, attorney
Mother: Mary (Maxwell) Gates, schoolteacher
Marriage: Melinda (French) Gates (January 1, 1994-present)
Children: Phoebe Adele, 2002; Rory John, 1999; Jennifer Katharine, 1996
Education: Attended Harvard University, 1973-1975
Was number one on the Forbes World's Billionaires List (World's Richest People) for 12 consecutive years from 1995 to 2007.
Has donated more than $28 billion to philanthropic causes through the Bill & Melinda Gates Foundation.
Microsoft is the world's largest software company.
1968 - Begins programming computers at age 13.
1972 - Co-founds a company called Traf-O-Data, which analyzes local traffic patterns, while still in school.
Summer 1972 - Congressional page in the U.S. House of Representatives.
1975 - Drops out of Harvard and co-founds Microsoft Corp. (formerly Micro Soft) with Paul Allen.
1977-1982 - President of Microsoft.
1980 - Develops MS-DOS (Microsoft Disk Operating System) for IBM. Two million copies are sold by 1984, and by the early 1990s, more than 100 million copies are sold.
1981-present - Chairman of the Board of Directors for Microsoft.
1985 - Gates introduces the Microsoft Windows operating system to compete with Apple.
Mid to late-1980s - Begins developing and promoting CD-ROM technology.
1987 - Becomes the youngest U.S. billionaire, worth $125 billion at 31 years old. That record is later broken by Mark Zuckerberg in 2010 and then Dustin Moskovitz in 2011.
1989 - Founder of Corbis, a digital image company.
May 1998 - The U.S. Department of Justice, 20 states and the District of Columbia file lawsuits accusing Microsoft of using illegal, anticompetitive and exclusionary practices.
January 2000 - Resigns as CEO of Microsoft and becomes chief software architect.
November 2001 - Microsoft reaches a settlement with the Justice Department in the antitrust case. Nine states agree to the settlement but nine other states and the District of Columbia consider the imposed sanctions too lenient.
November 2002 - U.S. District Court Judge Colleen Kollar-Kotelly approves most of the proposed settlement between Microsoft and the Justice Department, ruling against the dissenting nine states and the District of Columbia.
March 2, 2005 - Knighted by Queen Elizabeth II.
December 18, 2005 - Named Time Magazine's "Person of the Year" along with his wife Melinda and musician Bono.
June 15, 2006 - Announces that he will be giving up his daily role at Microsoft effective July 2008, to concentrate on his humanitarian and educational interests.
June 7, 2007 - Delivers the commencement address at Harvard University, the school he dropped out of in 1975. He also receives an honorary degree.
March 2008 - Falls to number three on the Forbes' list of billionaires, after a 12-year run at the top of list.
June 27, 2008 - Gates retires from day-to-day work at Microsoft to concentrate on philanthropy.
April 1, 2009 - Gates announces a partnership with the Chinese Ministry of Health to help fight an epidemic of tuberculosis in China, supported by a $33 million grant provided by the Bill & Melinda Gates Foundation.
January 29, 2010 - Gates Foundation announces it will donate $10 billion for vaccine research over the next ten years.
February 4, 2014 - Steps down as chairman and Sayta Nadella, a 22-year veteran of Microsoft, is named the new CEO.
March 2015 - Ranked number one on Forbes' list of the world's billionaires with a net worth of $79 billion.