Wulff could have chosen to settle the case with a €20,000 fine in April but was determined to clear his name and opted instead to face trial.
The charge centres on a €719 sum paid in 2008, and opinion is split on whether Germany's youngest-ever head of state really needed to quit or fell victim to media hounding and an overzealous criminal justice apparatus.
Since Wulff's downfall, prosecutors have built a case with 46 witnesses, alleging part of a hotel room bill for Munich's Oktoberfest in 2008, babysitting costs and a restaurant meal were paid by a film producer friend whom he later helped promote a movie project for.
The court must now decide whether accepting that generosity amounted to an abuse of political power or whether it was intended merely as a friendly gesture.
Wulff, 54, is Germany's first former head of state to answer charges in court. If found guilty he faces up to three years in jail or a fine for having accepted the favours five years ago when he was state premier of Lower Saxony.
"I think at the Elysee Palace or in Italy, politicians would not have resigned over similar accusations," said political scientist Lothar Probst of Bremen University, who pointed to a political culture in Germany that punishes holders of public office for even minor offences.
Probst said that in hindsight "political interests and the media apparently worked together to bring down a politician who, seen from a purely legal point of view, did hardly anything wrong."
But Probst also said that at the height of the scandal in early 2012 Wulff faced multiple allegations of corruption involving several other business friends and did himself no favours by failing to clear them up quickly.
News website Stern.de said that "more important than conviction or acquittal is something else: That it is clear that possible corruption is prosecuted not just in the case of a minor official but also in the case of a former president."
Wulff has largely retreated from public life since his resignation. He also separated from his wife, whose autobiography revealed tensions in their marriage. However the former couple were also seen attending a pop concert together. The former first lady is now linked with businessman Stefan Schaffelhuber.
According to Germany's best-selling Bild newspaper, he has been seen attending football matches with his children and receives several invitations to speak at events.
The accusations against him and the film producer David Groenewold, who also faces trial, were reduced from the more serious corruption and bribery charges initially demanded by prosecutors that carry up to five years in jail.
Groenewold allegedly paid the cash when the two men and their partners visited Munich to attend a movie festival and the world-famous Oktoberfest in 2008.
Months later Wulff allegedly wrote to industrial giant Siemens to ask for backing for a movie project of his friend Groenewold.
Amid the wider scandal which broke in late 2011, Wulff was battered by almost daily claims that he had also accepted other favours from business friends, including holidays and a cheap home loan, when he was state premier.
Wulff worsened matters when he left an angry voicemail message for the editor of Germany's biggest selling newspaper Bild over its coverage of the scandal.
The conservative Christian Democrat stepped down in disgrace in February 2012 after prosecutors demanded his immunity be lifted, kicking off a state investigation in which police searched Wulff's home.
In an appearance on ARD television on Tuesday evening, Wullf's defence lawyer Michael Nagel said the opening of the trial on Thursday would be difficult for his client. The 30-minute documentary also claimed that Wulff had been experiencing financial problems during his time as leader of Lower Saxony.
Wulff, who had been Chancellor Angela Merkel's hand-picked choice for the post, was replaced by Joachim Gauck, who was a Christian pastor and civil rights activist in the former communist East Germany.