By Alastair Lawson
Mr Prabhakaran has been part of the Tamil protest movement for decades
From an increasingly small area in the north-east of Sri Lanka, Velupillai Prabhakaran heads the Liberation Tigers of Tamil Eelam (LTTE) or Tamil Tigers.
He has a reputation as a fearless and ruthless guerrilla leader and under his leadership, the Tamil Tigers have become a highly-disciplined and highly-motivated guerrilla force.
But in recent months his forces have fought a desperate rearguard action as their dream of a separate homeland in the north and east of the country looks less and less likely.
Yet for much of the past three decades his organisation showed no sign of being defeated militarily by the Sri Lankan army, even though it was vastly outnumbered.
But recent advances by the army - including its capture of rebel-held eastern parts of the island in 2007 and the towns of Kilinochchi and Mullaitivu in early 2009 - have meant that Mr Prabhakaran is now under more military pressure than ever before. Kilinochchi was the rebels' administrative and political centre and Mullaitivu - a port town - was arguably its most heavily defended area.
The rebels' territorial grip was further weakened before Mullaitivu fell when the army re-captured the strategically important Elephant Pass, a land strip that links the northern Jaffna peninsula to the rest of the country.
There is now a strong possibility that the rebels will be reduced to a guerrilla group, with no land under their control for the first time in many years. All that remains in their hands is a tiny patch of the north-east near Mullaitivu and that too is in imminent danger of falling.
Mr Prabhakaran (centre) has a vice-like hold over his organisation
Mr Prabhakaran is reputed to wear a cyanide capsule around his neck, to be swallowed in the event of his capture.
He expects the same dedication from his troops, many of whom the Sri Lankan government says are either women or children.
He is also a man whom critics say is much more at ease fighting in the battlefield than he is sitting around a negotiating table.
They argue that any peace process is doomed to failure with Mr Prabhakaran as leader of the Tigers and that even after a Norwegian brokered ceasefire was signed in 2002, the rebels used the lull in fighting to re-group and re-arm.
Mr Prabhakaran's supporters argue that he fully embraced efforts to secure peace, pointing out that in 2002 he began de-commissioning arms, allowed a land route to be opened to the rebels' northern stronghold in the Jaffna peninsula and even gave support to his movement dropping its demand for a separate state.
From 2002 to 2008 - when the government announced that it was formally withdrawing from the ceasefire - Mr Prabhakaran suffered a number of setbacks.
In 2004 a renegade Tamil Tiger commander, known as Karuna, led a split in the rebel movement in the east - a huge breach of its much hailed discipline and unity.
Two years later the Tigers' chief ideologue, Anton Balasingham, died of cancer in London. His demise was described as an "irreplaceable loss" to the movement.
And in November 2007 the senior Tamil Tiger leader, SP Thamilselvan, was killed in a bombing raid by the military. He was the "public face" of the Tigers and the most senior rebel to be killed by troops in years. Mr Prabhakaran himself described his death as an "unparalleled loss".
The death of SP Thamilselvan was an "unparalleled loss"
Mr Prabhakaran inspires conflicting emotions in Sri Lanka - which reflect the divisions between the Sinhala and Tamil communities.
To his followers, he is a freedom fighter struggling for Tamil emancipation from Sinhala oppression. To his adversaries he is a megalomaniac with a brutal disregard for human life.
The Tamil Tiger leader seldom gives interviews to journalists, who are in any case restricted by the government from going into areas controlled by his forces.
However each November he does give a speech on what the Tamil Tigers refer to as Heroes' Day - to commemorate dead rebel fighters - and the message over the years has remained pretty much the same.
"The uncompromising stance of Sinhala chauvinism has left us with no other option but an independent state for the people of Tamil Eelam," he said in November 2006.
His movements between his various jungle hideouts are the subject of great secrecy, and he is reported to have narrowly avoided assassination or capture on numerous occasions. Following his latest military setbacks there has been much speculation as to whether he has fled to another country or is in hiding in the Sri Lankan jungle.
Commentators suggest that any escape to India would be dangerous because he is wanted there for the murder of former Prime Minister Rajiv Gandhi in 1991. But so too would a decision to remain underground in the Sri Lankan jungle, given the army's increasingly strong presence on the ground.
Accused of killings
Born on 26 November 1954, in the northern coastal town of Velvettithurai, on the Jaffna peninsula, Velupillai Prabhakaran is the youngest of four children.
He was an average student, shy and bookish. He said in one of his rare interviews that he was fascinated by Napoleon and Alexander the Great, devouring books on their lives.
He was also influenced by the lives of two Indian leaders, Subhash Chandra Bose and Bhagat Singh, both of whom were involved in the armed struggle for independence from Britain.
Angered as a teenager by what he saw as discrimination against Tamils in politics, employment and education, he began attending political meetings and practising martial arts.
He soon became heavily involved in the Tamil protest movement, and in 1975 was accused of being responsible for the murder of the mayor of Jaffna.
The rebel leader has suffered numerous setbacks over the years
That assassination was one of the first killings carried out by the burgeoning Tamil nationalist movement.
He was instrumental in the foundation of the Tamil Tigers around that time.
The killing of the mayor is not the only high-profile murder for which Mr Prabhakaran is the prime suspect.
India says Rajiv Gandhi was killed by a suicide bomber who was acting on orders from Mr Prabhakaran.
It is alleged that the rebel leader wanted to avenge Mr Gandhi's decision as prime minister in the mid-1980s to deploy Indian peacekeeping troops in Sri Lanka.
Despite the conflicting views surrounding Mr Prabhakaran, there is one point on which both the Sinhala and Tamil communities agree: he is the dominating force in the rebel movement, and until or unless he is either caught or captured, the Tamil Tigers will remain one of the world's most dangerous rebel groups.