Campaigning anti-corruption Judge Sergio Moro sentenced Lula, who ruled Brazil from 2003-2010, to nine and a half years in prison for accepting a bribe of a luxury seaside apartment and $1.1 million.
The conviction sent a chilling message to much of Brazil's political class as the vast corruption scandal shakes Latin America's biggest economy.
Here are key moments in the unprecedented corruption investigation known as operation Lava Jato, or "Car Wash:"
2014: Stumbling on a mega-scandal
March 17: Probably Brazil's biggest ever corruption scandal starts by accident.
Police detain black market money dealer Alberto Youssef in what starts as a routine money laundering probe involving a gas station.
But the probe leads investigators to massive state-owned oil company Petrobras. Paulo Roberto Costa, a Petrobras director, is arrested and testifies that the company has been funneling dirty money into the ruling Workers' Party and its allies.
2015: Massive scope becomes clear
March 6: The Supreme Court authorizes probes against 12 senators and 22 lower house deputies suspected of participating in a scheme to embezzle from Petrobras.
June 19: The CEO of Brazilian construction giant Odebrecht, Marcelo Odebrecht, is arrested and later sentenced to 19 years in prison for corruption. His company is found to have systematically bribed politicians to win inflated contracts from Petrobras.
Other arrests in 2015 include leading Workers' Party figures Jose Dirceu and Delcidio Amaral, and Andre Esteves, the head of Latin America's biggest investment bank, BTG.
2016: Political unrest erupts
March 4: Once hugely popular ex-president Lula -- who founded the Workers' Party and was in power during much of the period under investigation -- is taken in for questioning.
May 12: With popular anger against corruption growing, Congress votes to suspend Lula's successor, President Dilma Rousseff, for illegally manipulating government accounts. She is impeached and removed from office on August 31.
Michel Temer, Rousseff's deputy, takes over as president, but is immediately caught up in the Car Wash scandal. Several ministers are forced to resign after being implicated.
2017: Temer faces probe, Lula falls from grace
January 26: Plea deals by 77 Odebrecht executives provide Car Wash investigators with a flood of new testimony.
Fallout from Odebrecht goes international as it emerges that the company also paid bribes for contracts in a string of other countries. The company agreed with the US Justice Department in December 2016 to pay a record $3.5 billion fine to settle.
March 30: Former lower house speaker Eduardo Cunha, until then one of the most powerful men in Brazil, is sentenced to more than 15 years in prison for corruption.
April 11: The Supreme Court authorizes the latest wave of probes. Nine Temer ministers are targeted, along with 29 senators and 42 members of the lower house of Congress, according to a count by the respected Estadao newspaper.
May 17: Temer falls into the fray, facing calls for removal after reports surface that he discussed payments of hush money to buy Cunha's silence -- accusations the president's office denies.
May 19: The Supreme Court authorizes an investigation into suspected corruption and obstruction of justice targeting the conservative president.
June 20: Brazil's federal police say they have enough solid evidence Temer received bribes -- which a jailed suspended lawmaker allegedly accepted on his behalf -- to merit an investigation into the embattled president.
July 12: Lula is convicted of graft -- and vows an appeal -- in the largest scalp yet of "Car Wash" and a stunning blow to the leftist's prospects for political comeback.
