Timeline: A chronology of the life of Zynga

July 4, 2011 — Filing shows Zynga plans to diversify beyond Amazon with its own data centers.

July 1, 2011 — Zynga files to raise $1 billion in an IPO. Filing shows Zynga raised $845 million in three rounds over four years.

June 28, 2011 — Wall Street Journal reports Zynga preparing to file for IPO.

June 26, 2011 — Empires & Allies tops FarmVille in 25 days.

June 16, 2011 — Zynga sues Brazilian firm Vostu over copyright infringement for alleged copycat games.

June 15, 2011 — CityVille Hometown launched on mobile.

June 3, 2011 — EA’s No. 2 executive John Schappert joins Zynga as chief operating officer.

March 28, 2011 — Zynga raises $3 million for Japan quake victims.

February 2011 — Zynga raises round at $10 billion valuation.

Feb. 2, 2011 — Zynga takes Words With Friends game to Android mobile phones.

Jan. 24, 2011 — Zynga threatens lawsuit against Blingville for using “ville” in name.

June 1, 2011 — Zynga launches Empires & Allies.

Jan. 14, 2011 — CityVille hits 100 million users after 43 days. It is the fastest-growing game of all time in numbers of users.

Dec. 31, 2010 — Zynga’s revenues hit $597.4 million and net income is $90.5 million. Zynga has 1,483 employees.

Dec. 24, 2010 — CityVille becomes bigger than FarmVille, with more than 58 million users.

Dec. 2, 2010 — Zynga says it has acquired Texas-based mobile game publisher Newtoy. Price is later revealed to be $53.3 million. Zynga launches CityVille.

Nov. 30, 2010 — Zynga shuts Street Racing game.

Nov. 29, 2010 — Zynga cuts a deal with American Express to redeem virtual goods with credit card points.

Nov. 16, 2010 — Billionaire investor John Doerr of Kleiner Perkins says Zynga is “our best company ever.”

Oct. 26, 2010 — Zynga shares trading on secondary markets value the company at $5 billion, more than the value of Electronic Arts.

Oct. 5, 2010 — Zynga buys Bonfire Studios and renames it Zynga Dallas

Sept. 27, 2010 — Zynga signs one of the biggest leases in recent San Francisco history, taking over old Sega building with space to house thousands of employees.

Sept. 8, 2010 — SF Weekly runs story on FarmVillains, about how Zynga copied the games of rivals to get to the top.

September, 2010 — Zynga has 1,200 employees.

Aug. 25, 2010 — Digital Chocolate sues Zynga over Mafia Wars trademark.

Aug. 11, 2010 — FarmVille pulled from MSN.com.

August 4, 2010 — In its first foray into Japan, Zynga buys Unoh in Tokyo.

July 27, 2010 — Disney buys Zynga’s rival Playdom for up to $763.2 million. That suggests that Zynga is worth even more than that.

July 28, 2010 — Softbank confirms $150 million investment in Zynga as the company expands its social games in Japan.

June 9, 2010 — Zynga launches FrontierVille, the first game from Zynga East and chief game designer Brian Reynolds.

June 3, 2010 — Zynga buys Challenge Games.

May 24, 2010 — Mike Arrington and Bing Gordon describe the clash over Facebook Credits as the Cuban Missile Crisis of tech.

May 18, 2010 — Zynga and Facebook announce five-year deal in which Zynga agrees to support Facebook Credits on an exclusive basis. Zynga will pay 30 percent of its game transactions to Facebook.