The trial is set to run until 10 December. If found guilty, Mr Sarkozy could face a 10-year prison sentence and €1m (£889,000) fine.
Another former right-wing president, Jacques Chirac, was given a two-year suspended prison sentence
in 2011 for diverting public funds and abusing public trust. The offences dated back to his time as mayor of Paris.
But he did not appear in court, owing to ill health. He denied wrongdoing.
What’s this case all about?
French magistrates have spent years investigating allegations of corruption dating back to Mr Sarkozy’s election campaigns and period in office.
This case is linked to a long-running investigation into the right-wing politician’s suspected use of secret donations to fund his 2007 presidential campaign.
The prosecution alleges that Mr Sarkozy and lawyer Thierry Herzog sought to bribe Gilbert Azibert with a prestigious job in Monaco in return for information about that investigation.
It is known as the “wiretapping case” in France, because phone calls between Mr Sarkozy and Mr Herzog were tapped in 2013-2014, in which Mr Sarkozy used the alias “Paul Bismuth” and they discussed Judge Azibert.
French media report that Mr Sarkozy was heard telling Mr Herzog “I’ll get him promoted, I’ll help him.”
Mr Sarkozy denies any wrongdoing – and he points out that Judge Azibert did not get the Monaco position.
“Gilbert Azibert got nothing, I made no approach [on his behalf] and I’ve been rejected by the Court of Cassation,” Mr Sarkozy said in 2014, referring to his battle to clear his name.
In October 2013 magistrates dropped him from their investigation into claims that he had accepted illicit payments from L’Oreal heiress Liliane Bettencourt for his 2007 presidential campaign.