When he was tried in 1993 he was a bearded guerrilla fighter who had spent 18 years living as a fugitive in his own land.
By the time President Suharto resigned last May, Mr Gusmao had become a calm and besuited statesman, often photographed greeting visiting foreign leaders in the remarkably open confines of Jakarta's Cipinang Prison.
The British Foreign Office minister, Derek Fatchett, visited him there twice last year, as have processions of American senators and state department officials. In Timor itself he is adored, as a poet, a renowned lover of women, and as commander of Falintil, the Forcas Armadas Libertacao Nacional de Timor Leste, which was formed in 1975 when the Indonesian army invaded what was then an obscure Portuguese colony.
Ever since, the members of Falintil have lived in the thickly forested hills of East Timor. Their true names are often secret: instead they are known by romantic noms de guerre. The acting commander is called Taur Matan Ruak. Mr Gusmao himself, who was captured in an ambush in 1992, is universally known as Xanana.
For the first three years of the invasion, Falintil held out, and tens of thousands of people lived under their protection in the mountains. In 1978 the Indonesian army began using supersonic jets, allegedly British- made Hawk fighters.
"The Indonesians were too strong," the number three Falintil commander, Lere Anak Timur, said last autumn, "so we changed the strategy from the war phase to the guerrilla phase - the war of movement." The civilians returned to the lowlands where they were herded into relocation camps. Falintil remained in the hills, and in two decades theIndonesian military has failed to stamp them out.
During his trial in Jakarta in 1993, Mr Gusmao was forbidden from speaking in his defence, but he put out a statement that was released worldwide.
"I acknowledge military defeat on the ground. I am not ashamed to say so. On the contrary I am proud of the fact that a small guerrilla army was able to resist a large nation like Indonesia ... which in cowardly fashion sought to dominate us by the law of terror and crime."
In Cipinang, he won the respect of his guards and lived a remarkably free life, reflecting the importance with which foreign governments regard his continued well-being.
He remains the effective leader of Falintil, communicating with his officers through his many visitors.
The number of active Falintil fighters has dwindled over the years but the commitment of the population, if anything, is stronger than ever.
"Sometimes there might be ten of us, sometimes 20 or 80," says Mr Timur. "It is in the minds of all Timorese to fight against Indonesia and ifIndonesia wants to kill Falintil, they first have to kill us all."Reuse content