When he was appointed US Attorney General in February 2005, Alberto Gonzales became the most senior person of Hispanic descent in the Bush administration.
Mr Gonzales was central in the debate over interrogation methods
His success at achieving such a high post was portrayed by the White House as an American success story.
But Mr Gonzales, the nation's top law enforcement officer, became embroiled in a bitter row over the firing of eight US federal attorneys in December 2006, a row that rumbled on for several months and became increasingly acrimonious.
Opponents said he sacked the prosecutors for political reasons, then lied about the reason for their dismissal.
Mr Gonzales insisted he had done nothing wrong and pointed out that US attorneys serve at the will of the president, who can dismiss them at any time.
A long-term Bush ally, he enjoyed the support of the president over the issue - but saw his credibility undermined as the Democrats pushed for an investigation into the dismissals.
On 27 August, he formally announced that he was stepping down, effective from 17 September.
Mr Gonzales played an important role in shaping legal opinions about the treatment of prisoners captured in Afghanistan and Iraq.
He was central in the administration's debate over interrogation techniques for prisoners held in the war on terrorism.
He was criticised by some human rights groups after writing a memo to the president in which he said the war against terror was a "new kind of war" that renders obsolete Geneva's strict limitations on questioning of enemy prisoners and renders "quaint" some of its provisions.
The memo came to light after the Abu Ghraib prison abuse scandal.
Mr Gonzalez stuck to his views, although he also made it clear that he did not approve of torture.
Mr Gonzales, born in 1955, grew up in a poor Mexican migrant family in San Antonio, Texas - one of eight children living in a two-bedroom house, whose migrant parents worked hard to give them opportunities.
He went on to attend the prestigious Harvard law school, later becoming a lawyer and law professor at the University of Houston.
In 1995, he became Mr Bush's legal adviser when the president was governor of Texas.
In 1997, Mr Gonzales became Texas Secretary of State, working closely with Mr Bush on legal issues and later became a judge of the Supreme Court in Texas.
He is married and has three sons.