The trial of Taiwanese former President Chen Shui-bian on corruption charges has opened in the capital, Taipei.
Mr Chen, 57, denies accusations that he and his wife made millions of dollars through forgery and money laundering.
He says he is a victim of a "government purge" and that he does not believe he will receive a fair trial.
Since leaving office in 2008, Mr Chen has been a vocal critic of the new government's support for China, which claims sovereignty over Taiwan.
Mr Chen, his wife Wu Shu-chen, and 12 others were indicted on charges of corruption, money laundering, embezzlement and document forgery charges, a spokesman for the prosecutors' office said.
The couple stand accused of embezzling millions of dollars in public funds and accepting a huge bribe in a land purchase deal. Altogether, the money involved adds up to an estimated $15m (£10m).
In February, Mrs Wu pleaded guilty to accepting a $2.2m (£1.5m) political donation in connection with a land purchase deal, but denied that it had been a bribe, as alleged by prosecutors.
She admitted charges of forging documents in a separate case but denied using the money for personal gain.
Nine other accused have also pleaded guilty.
Mr Chen was taken into the Taipei courtroom in handcuffs to face the start of the formal proceedings against him.
His trial will initially investigate the alleged land deal before moving on to other charges, and is expected to last for several months.
The BBC's Cindy Sui in Taipei says people in Taiwan have been engrossed in the case, with some people shocked by the alleged crimes but others believing it is an example of political revenge.
Mr Chen says the charges against him are politically motivated, and constructed by the ruling Kuomintang (KMT) government "in order to gain favours and protection from the Beijing authorities".
Relations between Beijing and Taipei have been improving since the KMT, under President Ma Ying-jeou, took office last year.
Mr Chen has also challenged the impartiality of the judging panel, saying the fact they had not allowed him out on bail in December was "punitive".
"I must stand tall and appeal to the world. I must protest and tell my story for the sake of human rights and justice in Taiwan," AFP news agency quoted him as saying.
However, the KMT party said Mr Chen had failed to "set an example" as a national leader and would have to prove his innocence.
The court date follows more than two months of pre-trial hearings. If found guilty. Mr Chen could spend the rest of his life in prison.
Taiwan has been ruled separately from China since the end of the Chinese civil war in 1949, when the defeated Kuomintang retreated to Taiwan to create a self-governing entity.
But Beijing sees the island as a breakaway province which should be reunified with the mainland, by force if necessary.