FORT BRAGG, N.C. -- The Army captain who has accused Brig. Gen. Jeffrey A. Sinclair of sexually assaulting her during their three-year relationship was an ambitious soldier with plans to make the military her career, much like the boss she loved and admired.

Stirred by the 9/11 attacks to leave college and join the military, she signed up with the Army, learned the in-demand language of Arabic and showed a laser focus in trying to carve out a reputation as a soldier who could be counted on in the toughest of situations.

Her stunning allegations about Sinclair, a rising star revered by both his superiors as well as those he commanded on the battlefield, has put both of them -- and the three-year affair they both admit to -- under the microscope at a time when Congress and the Pentagon grapple with how to best deal with cases of sexual impropriety within the military ranks.

Her credibility is central to the case. Is she a woman whose affair with a charismatic and approachable superior ended with him forcing her to perform oral sex and threatening to kill her and her family? Or is she, as Sinclair's lawyers have portrayed, a jilted lover who fabricated allegations of sexual assault when Sinclair refused to leave his wife?

She testified Friday as Sinclair's court-martial began. She is expected to return to the stand Monday, where Sinclair's attorneys will likely ask tough, pointed questions and dissect the relationship in extremely graphic detail.

The Associated Press does not generally identify alleged victims of sexual assault. Much of what is known about the 34-year-old captain comes from her own testimony during the various military proceedings.

Her allegations set in motion a rare court-martial against a brigadier general. He is believed to be only the third high-ranking military officer to face court-martial in the past half century -- and the highest ranking officer to be accused of sexual assault.

The charges against Sinclair and his hearing come at a time the Army is under increasing pressure to confront what it has called an epidemic of sexual misconduct. On Thursday, the U.S. Senate rejected a proposal that would end the practice of allowing commanders to decide if serious crimes move forward through military courts.

Sinclair, 51, this past week pleaded guilty to charges he had improper relationships with two other female Army officers and to committing adultery with the captain, a crime in the military. He also admitted to possessing pornography in Afghanistan, a violation of orders for soldiers in the socially conservative Muslim country.

The captain was given immunity in exchange for her testimony.

By pleading guilty to those lesser charges, Sinclair's attorneys hope to boil the case down to a classic "he said, she said," and zero in on whether his accuser is to be trusted and believed. It will be up to a jury made up of five two-star generals to decide if Sinclair at any time forced her to perform sex acts or if everything that happened was consensual.

The captain didn't plan on joining the military. She grew up in Nebraska, playing several sports and was in the midst of going to school out of state at a small liberal arts university. But after the 9/11 attacks, she decided to join the Army. She hungered to help serve her country when it needed her and she was whetted by the chance to see the world.

"September 11th extremely impacted my life as it did many other people and I just felt I could get my degree any time, but it was more important for me to join the Army," she testified in November 2012 at what is known in military court as an Article 32 hearing, similar to a grand jury proceeding.

She found herself in demand after learning Arabic soon after joining the Army. After a few years, she told a superior she wanted to advance and become an officer. He told her she needed to win some Soldier of the Month competitions. She started practicing and won several before being named the soldier of the year in her region in the mid-2000s.

After she completed officer training, she was sent overseas to work for a brigade commanded by then-Col. Jeffrey Sinclair.

The newly commissioned second lieutenant was struck by her new commander and a leadership style that was inspirational.

"Everyone talked about him like a God, that nothing could hurt him, nothing could rattle him," she testified Friday. "He exuded complete control. I had never met anyone with such compete confidence."

The two grew close over several months. Their small talk became increasingly intimate. One night, she went to his quarters to drop off a DVD and they ended up watching the sexy vampire soap True Blood. He asked her to put down her hair and they kissed. Soon, their secret liaisons involved sex.

She describes a hot-and-cold relationship over three years that eventually degenerated into constant arguing before Sinclair forced her into performing oral sex on him.

There were times when it could be remarkably caring, she says. They had pet names for one another, which included him calling her "Panda," and she calling him "Mr. Sexy Pants." In one birthday card, she likened him to George Washington.

"I knew he was a colonel and I was just a lieutenant, but I was in such awe of him," she testified. "I knew it was wrong."

The relationship could also be cold and demeaning. She said he liked to embarrass her by covertly groping her in public or having sex in places they might be seen by others. When she would make mistakes, she said Sinclair humiliated her by making her say "I'm just a girl" and it encouraged other soldiers to mock her as well.

She stunningly accuses him of having threatened to kill her family after she said she wanted to meet his wife, but then introduced him to her parents when they came to visit.

She didn't immediately go to her supervisors after, she says, Sinclair forced himself on her. "I knew if I said anything, it would be my word against his and no one would believe me. I had no way out," she testified Friday at Sinclair's court-martial.

They continued to try to hash out their relationship -- she would increase the pressure for him to leave his wife and he would brush her off -- and she testified she felt more despondent each day. About four months after she said Sinclair forced himself on her, she saw an email from another young captain on his computer that ended with "I love you." She was confessing to Sinclair's supervisor hours later.

"I knew I didn't have the energy for it anymore and also like was completely accepting of the fact that the whole time I had been with him, I was just his whore. And I hated myself. My parents didn't raise me like that. I felt incredibly ashamed," she said.

Colleagues gossiped that the captain and Sinclair were lovers.

Sinclair spoke highly of her to other soldiers and many of them also felt she was intelligent and hard-working. But they also thought she could be volatile and did not properly defer to her superiors.

"She didn't understand her place in the world. And then, just other -- for instance bothered me that when going out on a combat patrol, I could smell her perfume from across a hundred meters away, which was not necessarily something I want as I'm walking down some Iraqi street," testified Capt. Christopher Rosser, who worked with Sinclair and his accuser in Iraq and called Sinclair a mentor.

Sinclair's attorneys have hammered her credibility throughout the case, pointing to inconsistences in her story each time she has told it. They also say her account of an abusive relationship is also contradicted by much more positive memories of the relationship in a diary she kept during the affair, as well as thousands of often sexually explicit emails and text messages she exchanged with the general.

By the time the affair ended, the general's mistress tearfully testified Friday, she had begun contemplating suicide.

"I hated my life, this person I had become," the captain said. "I didn't want to be a woman on the side, just being used for sex."

Still, she testified in 2012 that she loved the general and didn't want him to face serious punishment. With the passage of time, however, her position hardened.

In a December letter sent by her attorney, the woman opposed a plea agreement where Sinclair would have pleaded guilty to lesser charges in exchange for the dismissal of the sexual assault allegations.

Writing on behalf of her client, Capt. Cassie L. Fowler suggested the proposed deal would "have an adverse effect on my client and the Army's fight against sexual assault."

"Acceptance of this plea would send the wrong signal to those senior commanders who would prey on their subordinates by using their rank and position, thereby ensuring there will be other victims like my client in the future," Fowler wrote.