Profile: Bradley Manning
US Pte First Class Bradley Manning lip-synced to Lady Gaga while he downloaded thousands of classified documents from military servers, according to a computer hacker he befriended.
Now, the 25-year-old soldier has been sentenced to 35 years in prison after being convicted of 20 charges in connection with the leaks, including espionage. He was acquitted of the most serious charge, aiding the enemy.
After his sentencing, Pte Manning said he wanted to live as a woman and had taken the name Chelsea.
As an intelligence analyst in the US Army, Pte Manning was given access to a large amount of highly sensitive information.
But as a private first class, he was very low-ranking with a relatively meagre wage.'Funny little character'
According to his friends, he had become frustrated with a military career that appeared to be stagnating.
And his personal life appears to have hit a downward spiral after he was posted to Iraq in 2009.
Pte Manning joined the army in 2007 after drifting through low-paid jobs.
He had been brought up in Crescent, a small town in Oklahoma. His father, Brian, had reportedly spent five years in the military.
But his parents divorced when he was a teenager, and he moved with his mother to Haverfordwest in south-west Wales.
As a teenager, he was said to have been a hothead who was often teased for being a geek.
"He would get upset, slam books on the desk if people wouldn't listen to him or understand his point of view," a classmate from Oklahoma, Chera Moore, told the New York Times.
A friend from his schooldays in Wales, James Kirkpatrick, told the BBC he was a "funny little character, really on the ball" who was obsessed with computers.Turned in
After finishing school, he returned to the US and joined the army. Friends say he enlisted to help pay for college, and he later said he had joined up in the hope the Army would rid him of his desire to be a woman.
He was deployed to Iraq in October 2009. But messages he posted on Facebook suggest he was far from happy.
End Quote Bradley Manning Facebook message
Bradley Manning is beyond frustrated with people and society at large”
He wrote in early May 2010 on the site that he was "beyond frustrated with people and society at large".
Other status updates followed, among them: "Bradley Manning is not a piece of equipment."
A week earlier, he had written: "Bradley Manning is now left with the sinking feeling that he doesn't have anything left."
Some of the postings appear to refer to a recent breakdown of a relationship.
But weeks later his words appeared prophetic when he was arrested by military investigators on suspicion of stealing secret information.
Self-confessed computer hacker Adrian Lamo told the world's media how Pte Manning had admitted the data theft during conversations they had on the internet.
- Website with a reputation for publishing sensitive material
- Run by Julian Assange, an Australian with a background in computer network hacking
- Released 77,000 secret US records of US military incidents about the war in Afghanistan and 400,000 similar documents on Iraq
- Also posted video showing US helicopter killing 12 people - including two journalists - in Baghdad in 2007
- Other controversial postings include screenshots of the e-mail inbox and address book of US vice-presidential candidate Sarah Palin
"Listened and lip-synced to Lady Gaga's Telephone while exfiltrating possibly the largest data spillage in American history," Pte Manning wrote, according to a transcript of their messages published on Wired's website.
"Weak servers, weak logging, weak physical security, weak counter-intelligence, inattentive signal analysis… a perfect storm."
Mr Lamo went to the authorities with the messages.
During a sentencing hearing at his court martial in August 2013, a military psychiatrist testified that Pte Manning had struggled with his gender identity and wanted to become a woman.
He also said Pte Manning had felt abandoned by friends and family after his 2009 deployment to Iraq and that his relationship with his boyfriend had hit a rough patch.An apt location
In March 2011, the US Army charged Pte Manning with 22 counts relating to the unauthorised possession and distribution of more than 720,000 secret diplomatic and military documents.
Among the files he passed to Wikileaks was video footage of an Apache helicopter killing 12 civilians in Baghdad in 2007.
Wikileaks released tens of thousands of documents relating to the Afghan war.
The website later disclosed thousands of sensitive messages written by US diplomats and military records from the Iraq war, causing growing embarrassment to the US government.
Pte Manning told the court he had leaked the documents to spark a public debate in the US about the role of the military and about US foreign policy.
At a later sentencing hearing, he apologised for "hurting the US" and said he had mistakenly believed he could "change the world for the better".
And he said that in retrospect, he should have worked "inside the system".
Officials say the location of his trial, Fort Meade, was chosen because its military court is one of the largest in the Washington area.
A day after he was sentenced to 35 years in prison, Pte Manning said he wanted to live as a woman.
"I am Chelsea Manning," he said in statement to NBC's Today programme. "I am a female."
He said he had felt female since childhood, wanted at once to begin hormone therapy, and wished to be addressed as Chelsea.
When asked why Pte Manning was making this announcement after his sentencing, his lawyer, David Coombs said: "Chelsea didn't want to have this be something that overshadowed the case."