According to Michael Cohen, one of his frequent jobs was renegotiating bills on Trump's behalf.

"A law firm would send an invoice. He didn't believe that the invoice was fair, reasonable or justified, so he would give me the task of renegotiating a specific bill," Cohen said.

Cohen recounted his work repaying approximately 50 vendors related to Trump University at a discounted rate. All but two of the fifty vendors agreed to the discounted rate.

"They just went away," Cohen said of the two vendors.

"Did you pay then?" prosecutor Susan Hoffinger asked.

"No, ma'am," Cohen responded.

Cohen said Trump told him the outcome of the negotiation was "fantastic" and "great."

"How did that make you feel?" Hoffinger asked.

"Like I was on top of the world," Cohen responded.

Cohen told jurors that he began working for Trump after helping Trump with a series of legal favors.

"We ended up overtaking the board and resolving the issue which was to Mr. Trump's satisfaction," Cohen said about the first favor related to a board at a Trump property. "He liked the way that occurred and then continued to ask me if I would assist in other legal issues or matters he had."

"Did he pay you for that work?" prosecutor Susan Hoffinger said.

"No, ma'am," Cohen said

According to Cohen, Trump offered him a job after he presented Trump a $100,000 bill for legal costs related to the earlier favors.

"Would you want to come work for me?" Cohen recounted Trump saying. "I was honored, I was taken by surprise, and I agreed"

When asked about the $100,000 legal bill, Cohen said Trump "asked if I would like to get fired on the first day." The bill was never paid, according to Cohen, who immediately left his law firm to work for the Trump Organization as Trump's special counsel and a senior vice president.

When asked about the kind of work Cohen did for Trump, Cohen responded, "It was whatever concerned him -- whatever he wanted."

Cohen said he reported "just to Mr. Trump."

Michael Cohen briefly introduced himself to the jury, telling them how his father immigrated to California after surviving the Holocaust.

"Four children later, here I am," Cohen said about his parents.

Cohen told the jury that he went to law school at the urging of his family, though he did not want to practice law.

"I wanted to go to Wall Street," Cohen said.

He briefly explained how he acquired wealth with real estate investments and taxi medallions.

"I ended up going into business with a friend of mine who had grown up with me and we started purchasing buildings," Cohen said.

Cohen stood up in the witness box so he could identify Trump in the courtroom.

"He is wearing a blue and white tie," Cohen said while looking toward Trump.

"The people call Michael Cohen," prosecutor Susan Hoffinger said.

Michael Cohen entered the courtroom and took his seat in the witness box.

Donald Trump stared straight forward as Cohen walked into the courtroom. He did not appear to look toward Cohen.

When Donald Trump won the 2016 election, Cohen testified there was no role for him in the incoming administration.

"My service was no longer necessary," Cohen said.

He was offered a position in the White House as "assistant general counsel" by Reince Preibus, but turned it down. He said he was disappointed he was not considered for chief of staff.

"I didn't want the role. I didn't believe the role was right for me or that I was even competent to be chief of staff. I just wanted my name to be included," he testified.

"It was more about my ego than anything," Cohen said about his disappointment. "I would have liked to have been considered."

Cohen said he pitched being "personal attorney to the president." He would need the role, Cohen said, because there were "outstanding matters" to be dealt with. Cohen conceded it would have helped him personally and professionally.

"I also had another thought in mind, which was consulting. That's what I really wanted because that afforded me the time to stay at home, in New York," he said.

Cohen testified it could have been lucrative to help people understand Trump's thinking.

"Mr. Trump was an enigma," Cohen said. "Because of my close proximity to him for a decade, I did understand."

"Did you think you could monetize being personal attorney to the president?" prosecutor Susan Hoffinger asked.

"Absolutely," Cohen said.

Trump's eyes remained closed during this portion of the testimony.