The Dalai Lama will mark his official 80th birthday on Sunday with prayers and celebrations in his hometown-in-exile, but little to show for his decades of lobbying for greater Tibetan autonomy.

The Nobel laureate will be in the United States when he turns 80 on July 6, but Sunday is his official birthday according to the Tibetan lunar calendar, and he will celebrate with fans and followers in Dharamsala.

The Dalai Lama will address Tibetan exiles and Indian dignitaries in the north Indian hill town where he has lived since fleeing Tibet in 1959 after a failed uprising against Chinese rule.

The event will include traditional dancing and a special long life prayer for the Buddhist spiritual leader, who shows no sign of slowing down.

Although he has officially given up his political role, the Dalai Lama maintains a hectic schedule of foreign travel and is due to visit Britain this month before travelling on to the United States.

But his retirement from politics in 2011 was a reminder to exiled Tibetans that the man who remains the universally recognised face of the movement will not be around forever.

"The two big questions are what will happen after he's gone and whether Tibetans inside and outside China will look to his replacement in the same way," said Jayadeva Ranade, president of the Centre for China Analysis and Strategy in New Delhi.

Sunday's ceremony in Dharamsala -- home to thousands of Tibetan refugees -- will be a time for celebration, but also for reflection on the Dalai Lama's push for greater autonomy for Tibet under Chinese rule.

The elderly monk's promotion of non-violence along with his ready laugh have made him a global peace icon and kept Tibet firmly in the global spotlight.

He has been a unifying force for Tibetans inside and outside the mountainous region, but has little to show for his decades of lobbying for autonomy.

Formal negotiations with Beijing broke down in 2010 after making no headway, and many exiled Tibetans remain deeply sceptical about renewing them.

- Questions over succession -

Beijing accuses the Dalai Lama of seeking to split Tibet from the rest of China and has called him a "wolf in sheep's clothing".

In 2011 the Dalai Lama delegated his political responsibilities to a prime minister elected by Tibetan exiles in an attempt to lessen his own totemic status and secure the movement's future after his death.

But he remains the most powerful rallying point for Tibetans, both in exile and in their homeland.

Last year he told German newspaper Welt am Sonntag that doctors had told him he could live to 100, adding, "in my dreams I will die at the age of 113 years".

Nonetheless his advancing years have raised questions over his succession as Tibet's spiritual leader.

Traditionally, the search for a new Dalai Lama is conducted by high lamas, senior monks who fan out across Tibet to look for a child that shows signs of being the reincarnation.

Beijing has indicated it will have final say over the appointment of a new Tibetan spiritual leader -- raising fears of two competing Dalai Lamas.

This happened in 1995 when Beijing rejected the Dalai Lama's choice to be the next Panchen Lama, the second-highest ranking Tibetan Buddhist, and instead picked its own.

The 14th Dalai Lama has repeatedly said he may not reincarnate -- to the apparent frustration of Beijing.

"The Dalai Lama institution will cease one day," he told the BBC in December.

"Much better that a centuries-old tradition cease at the time of a popular Dalai Lama."