(England Twitter)-American forces were led to Osama bin Laden by his most trusted courier, a Kuwaiti-born man named Sheikh Abu Ahmed.
The shadowy figure was identified after Al Qaeda commanders held at Guantanamo Bay admitted they knew him - and that he had connections to Bin Laden.
A handful of heavily armed loyal subordinates guarded the compound in the northern Pakistani garrison town of Abbottabad.
Bin Laden's only contact with the outside world and the lieutenants running his organisation was through a man he trusted with his life.
It was not until 2004, when top Al Qaeda operative Hassan Ghul was captured in Iraq, that the CIA made any progress.
Ghul told the CIA that al-Kuwaiti was a courier and that he was close to Faraj al-Libi, who replaced Khalid Sheikh Mohammed as Al Qaeda's operational commander.
The bin Ladens occupied the top two levels of the $1 million mansion, while on the bottom floor were the men who would fight to the death for their leader.
Footage suggests a fairly spartan life. The yard consists of little more than dirt and vegetable allotments.
It was only later under conventional interrogation techniques that he admitted he knew him - though he still did not surrender a full name or where the courier could be found.
The CIA were now convinced that if they found Abu Ahmed they would find Bin Laden.
They flooded the field with agents, scouring Pakistan and Afghanistan for the merest whisper of Ahmed's whereabouts.
Locals in Abbottabad have described the compound as a "red zone area" of exceptionally high security, even though women and children could be heard chatting, playing and crying.
Neighbours referred to the men who entered and left the compound as simple, rural people as opposed to the urbane middle-class locals who call the military town home.
There was a real risk that Bin Laden would flee once again, thwarting U.S. attempts to capture or kill him
In the early hours of May 1, two dozen members of the Navy's elite SEAL Team Six went in.
Bin Laden was shot twice, once through the head. His daughter, 12, watched him die.
The squad left the compound with a trove of computers and files.
Three others also died - a woman who is said to have been used as a human shield and Ahmed's brother among them.
Ahmed himself, Bin Laden's closest lieutenant, who had finally given him away, was also killed.
Ever since September 11, the CIA knew about the existence of one particular courier who was close to him.
That it was al-Kuwaiti was confirmed first by al-Qaida's third in command, Khalid Sheikh Mohammed, and then by al-Qaida operative Hassan Ghul. Both were interrogated at Guantanamo Bay using controversial techniques such as waterboarding.
And we know that he had released videos and audios. We know that he was in contact with some senior al Qaeda officials,' Brennan added.
'So what we're trying to do now is to understand what he has been involved in over the past several years, exploit whatever information we were able to get at the compound and take that information and continue our efforts to destroy al Qaeda.
