Actor Johnny Depp flatly denied hitting his ex-wife Amber Heard, evaluating the assault allegations against him as heinous when he took the witness stand at the defamation trial he launched against the actress on Tuesday.

"There were arguments and things of that nature but never did I myself reach the point of striking Miss Heard in any way," the "Pirates of the Caribbean" star told the jury hearing the case at the Fairfax County Circuit Court in Virginia.

"Nor have I ever struck any woman in my life," he said.

Depp said the "heinous and disturbing" allegations of physical abuse made against him by Heard were "not based in any species of truth" and came as a "complete shock."

Depp was asked by one of his lawyers why he had brought the defamation case against his ex-wife.

"I felt it my responsibility to stand up not only for myself, but stand up for my children," Depp said. "I wanted to clear my children of this horrid thing that they were having to read about their father that was untrue."

"It's strange when one day you're Cinderella, so to speak, and then in 0.6 seconds you're Quasimodo," he added.

The 58-year-old Depp, his hair slicked back in a ponytail and wearing a black suit, black shirt and floral pattern tie, took the stand on the fifth day of the blockbuster defamation trial.

Heard, who was dressed in a white pinstriped blouse with a bow, listened attentively but impassively as Depp testified in a slow and measured voice punctuated by elaborate hand gestures.

Depp filed the suit after Heard, who turns 36 on Friday, wrote a column for The Washington Post in December 2018 in which she described herself as a "public figure representing domestic abuse."

The actress never named Depp, whom she met in 2009 on the set of the film "The Rum Diary," but he sued her for implying he was a domestic abuser and is seeking $50 million in damages.

Heard, who was married to Depp from 2015 to 2017, countersued, asking for $100 million and claiming she suffered "rampant physical violence and abuse" at his hands.

Depp accuses Heard of seeking to "generate positive publicity for herself" ahead of the release of the film "Aquaman," in which she had a starring role.

Depp filed the defamation complaint against Heard in the United States after losing a separate libel case in London in November 2020 that he brought against the tabloid The Sun for calling him a "wife-beater."

'Never seen Johnny abuse anybody'

On the stand, Depp pushed back against claims by Heard's lawyers that the actor would become a "monster" during drug- and alcohol-fueled benders and physically and sexually abuse Heard.

Depp said his first experience with drugs came at the age of 11 when he would steal "nerve pills" from his volatile and abusive mother.

"I have taken substances over the years, on and off, to numb myself of the ghosts, the wraiths, that were still with me from my youth," he said. "Essentially it was just self-medication."

But Depp said he is "not some maniac who needs to be high or loaded all the time.

"The characterization of my quote unquote substance abuse that's been delivered by Miss Heard is grossly embellished and, I'm sorry to say, but a lot of it is just plainly false."

Depp was asked about the early days of his relationship with Heard.

"She was attentive, she was loving," he said. "It was as if she was too good to be true."

Only later, the actor added, did "things begin to reveal themselves" and "within a year or a year and a half she had become another person almost."

Depp's attorneys told the jury the allegations against Depp have had a "devastating" impact on his career.

He left his role as Captain Jack Sparrow in the "Pirates of the Caribbean" franchise and was asked to step down from the "Fantastic Beasts" series based on the book by Harry Potter author J.K. Rowling.

Depp took the witness stand following testimony from a member of his security detail, Sean Bett, and Keenan Wyatt, who worked as a sound engineer on many of his movies.

Both men said they had never seen Depp be violent.

Depp will return to the witness stand on Wednesday for more questioning by his lawyers. He will then be subject to cross-examination by Heard's attorney.

In 2016, Heard sought a divorce and a restraining order against Depp amid abuse allegations. Their divorce was finalized in 2017.