Mr. Taylor was indicted in 2003 while serving as president, and he told the court that African leaders had assured him that the indictment would be annulled if he left office.

The presiding judge asked if there had been an agreement setting out the terms of his resignation. “There was nothing written,” Mr. Taylor said, but, he said, leaders from West Africa and the African Union had told him “everything would be done to quash the indictment.”

“I stepped down as promised,” he said. In August 2003, he was offered exile by President Olusegun Obasanjo of Nigeria. But Mr. Taylor was arrested there in 2006 and “treated like a common criminal,” he said.

“I’m damned angry at what Obasanjo did to me,” he told the court, suggesting that others had also betrayed him. “As I sit here, I’m still perplexed. I can’t understand all the intrigues that happened to me.”

In giving his version of events, Mr. Taylor surprised some of the court’s investigators. He said he had not been fleeing when he was arrested at the Nigerian border, but had merely been on his way to visit a friend, the president of Chad, Idriss Déby.

“I was not trying to escape,” he said. “I was escorted by four vehicles of armed Nigerian secret servicemen and Nigerian police.” But when the border police stopped him, they said they were acting on orders of the president, Mr. Taylor said.

“They were extremely rude; I was handcuffed,” he said.

Mr. Taylor’s testimony comes as another tribunal, the International Criminal Court in The Hague, has been frustrated by its efforts to arrest President Omar Hassan al-Bashir of Sudan on charges similar to those leveled against Mr. Taylor, including war crimes and crimes against humanity. African leaders have so far stood behind Sudan’s president and have said they will not arrest him.