Commonly known by his nickname, Gus Dur, he heads the 30-million-strong Nahdlatul Ulama, which claims to be the world's largest Islamic organisation. About 90 per cent of Indonesia's 210 million people are Muslim.
Gus Dur, 59, is nationally and internationally known as a revered and moderate Islamic leader who had used his influence as an intellectual and a religious leader to promote sectarian and social tolerance.
Mari Pangestu, director of the Center for Strategic and International Studies in Jakarta, described Wahid as a "popular figure - an Ulama (Muslim religious leader) but he is a moderate". Professor Salim Said, a Jakarta political analyst, said Wahid "presents the sweet face of Islam".
It is hoped that Wahidís moderate views would enable him to unite all groups in ethnically, culturally and religiously diverse Indonesia.
Under the Suharto regime, Wahid pushed progressive ideas that won him international respect, including his strong advocacy for co-operation among religious faiths.
He has consistently defended Indonesia's Chinese minority - most of them Christians - against attacks by hardline Muslim groups.