Draped in traditional maroon and yellow robes, the Dalai Lama sat and listened to speeches and chants of monks, nuns, pilgrims, as well as well-wishers from across the world.

The leader, who turns 90 on July 6, and thousands of other Tibetans have lived in exile in India since Chinese troops crushed an uprising in the Tibetan capital Lhasa in 1959.

The Dalai Lama's 90th birthday is more than a personal milestone.

The charismatic Nobel Peace Prize-winning Buddhist Tenzin Gyatso -- who Tibetans say is the 14th reincarnation of the 600-year-old post -- is also expected to reveal if there will be another Dalai Lama after him.

"We offer our fervent devotions that Tenzin Gyatso, protector of the Land of Snows, lives for a 100 eons," a chorus of red-robed monks sang.

"May all your noble aspirations be fulfilled," they added, in front of a crowd that included religious leaders of many faiths.

The Dalai Lama has said the institution will continue only if there is popular demand -- and is widely expected to reveal that decision on Wednesday.

The occasion carries profound weight not only for Tibetans, but also for global supporters who see the Dalai Lama as a symbol of non-violence, compassion, and the enduring struggle for Tibetan cultural identity under Chinese rule.

His advancing age has also sparked concern over the future of Tibetan leadership and the delicate question of his succession.

While China condemns him as a rebel and separatist, the internationally recognised Dalai Lama describes himself as a "simple Buddhist monk".

Many exiled Tibetans fear China will name a successor to bolster control over a territory it poured troops into in 1950.