He has insisted that all he wanted was to show the true side of America's wars. Now, Bradley Manning faces decades behind bars for the biggest leak in US history.

The baby-faced former intelligence analyst said during his high-profile trial that the violence he saw in Iraq drove him to hand over a mass of military reports and diplomatic cables to the anti-secrecy site WikiLeaks.

But a military judge ruled that, while Manning did not knowingly aid Al-Qaeda, he did commit espionage, and on Wednesday she sentenced the 25-year-old to 35 years in prison.

Supporters of Manning present him as a heroic whistleblower. Critics, however, say he betrayed his uniform and his country, putting US national security and the lives of fellow soldiers at risk.

The towering narratives have often seemed to overwhelm Manning himself, a skinny, short, and often pale-looking US Army private with an aptitude for computers and an outwardly calm demeanor that belied a troubled personal history revealed in stark detail during his trial.

The court heard that Manning struggled with his homosexuality while in Iraq and that he displayed suicidal tendencies during his time spent in military custody, much of it in solitary confinement.

Born in Crescent, Oklahoma, to an American father and a Welsh mother who later divorced, Manning had a talent for computers from an early age and reportedly created his first website when he was just 10 years old. During his trial even prosecution witnesses recounted how skillful he was in front of a screen.

At the age of 17, when he was living as an openly gay man, Manning got a job with a software company in Oklahoma City, only to be fired four months later.

He then moved on to computer hacking and even attended events with fellow hackers, a paradoxical prelude to the high-level security clearance he obtained when he became a military intelligence analyst.

"I am the type of person who always wants to figure out how things work. And as an analyst, this always means I want to figure out the truth," Manning said in his pre-trial testimony at the Fort Meade military base near Washington.

His homosexuality and gender identity issues -- Manning enlisted despite the "Don't Ask, Don't Tell" policy on gays in the military at the time -- led to bullying, as they had when he was in school.

Commanders judged him ill-suited to military life and during training he was recommended for discharge. But his technical skills were perfectly suited to becoming an intelligence analyst and the decision was overturned.

Ultimately he was sent to Iraq where -- appalled with what he saw in the reports he analyzed -- his motivation for illicitly uploading such material and passing it to WikiLeaks appears to have taken hold.

Manning leaked hundreds of thousands of frontline military reports from Iraq and Afghanistan and diplomatic cables to WikiLeaks, the website founded by Julian Assange, an anti-secrecy activist and harsh critic of the United States.

A US Army video recording of two Apache helicopters gunning down a group of Iraqis in Baghdad, an attack that killed at least 12 men and wounded two children, was an incident Manning said "burdens me emotionally" and was among his first leaks.

"They dehumanized the individuals they were engaging and seemed to not value human life by referring to them as 'dead bastards' and congratulating themselves on their ability to kill in large numbers," Manning said in court.

Such an account matches the view of Manning held by supporters, who say he was a voice of conscience who lifted a veil on what he considered the worst transgressions of US foreign policy.

Daniel Ellsberg -- the military analyst who famously leaked the Pentagon Papers, a top secret study that detailed how the government had misled the public about the Vietnam War -- has called Manning a hero deserving of the Nobel Peace Prize.

The Bradley Manning Support Network, meanwhile, has received donations to pay his legal costs and has campaigned relentlessly on his behalf.

The prosecution presented a far darker view of Manning, saying he set out to harm the country he had pledged to serve.

"He was not a troubled young soul, he was a determined soldier with the knowledge, ability and desire to harm the United States in its war effort," lead prosecutor Major Ashden Fein told the court.

Manning apologized for his leaks last week and after learning his fate, he reiterated his motivation for the disclosures in a statement read out by his lawyer.

"It was never my intent to hurt anyone," Manning said. "I only wanted to help people. When I chose to disclose classified information I did so out of a love for my country and a sense of duty to others."