Testifying for the first time in a trial that has transfixed and horrified France, Dominique Pelicot said on Tuesday that he had “nothing but love” for his wife but a sex addiction controlled him, and he couldn’t stop himself from drugging her and raping her, and bringing other men into their home to rape her along with him while she was unconscious.

Mr. Pelicot, 71, added that his illness was created by traumatic episodes in his childhood, notably a sexual assault he said he suffered at age 9, when he was admitted to hospital with a head injury, and a nurse sexually assaulted him. His wife, he said, had saved him from that horror for a long time.

“She didn’t deserve this, I recognize that,” he said in tears sitting on the stand, his voice so weak that the court strained to hear him.

“I regret what I did and ask for forgiveness, even if it unforgivable,” he said later, addressing his ex-wife, Gisèle Pelicot, who stood in the middle of the court and looked directly at him as he testified.

Including Mr. Pelicot, some 51 men are on trial together, mostly on charges of the aggravated rape of Ms. Pelicot. One has pleaded guilty for similarly drugging his own wife to rape her and inviting Mr. Pelicot to their home to rape her while she was drugged.

Mr. Pelicot’s appearance on Tuesday came as a surprise. Just one week into the trial, he fell so ill that he missed four days of court, until the head judge finally postponed the hearing. Mr. Pelicot was diagnosed with kidney stones, a kidney infection and prostate problems.