Today, the number of monks has decreased to several hundred, while Beijing has appointed an oversight team -- Sera's Democratic Management Committee -- to control its activities.
The committee is tasked with closely monitoring the monks during their afternoon session of religious debate.
According to the India-based Tibetan Center for Human Rights and Democracy, the committee also holds compulsory meetings to indoctrinate the monks in political education.
Chinese Communist troops occupied Tibet in 1950. Tibet's high priest, the Dalai Lama, fled his homeland following a 1959 uprising against Chinese rule. During the decade-long Cultural Revolution in the 1960s-1970s, temples were demolished and monks and nuns jailed.
Beijing has since relaxed its policy on religious freedom, but the Dalai Lama remains in exile. The 69-year-old spiritual leader, the 14th Dalai Lama, now heads a Tibetan government in the northern Indian city of Dharamsala, trying to win more autonomy for Tibet.
In 1995, Beijing nominated a five-year-old boy to be the 11th Panchen Lama, the second-highest spiritual figure in Tibet's Buddhist hierarchy. A different boy, selected by the Dalai Lama to be the Panchen Lama, disappeared from public view that same year. He is still missing and is considered by some to be the world's youngest political prisoner.
A 28-year-old monk seems to struggle with a sense of allegiance to the Dalai Lama and the need to show approval for the Panchen Lama chosen by the Chinese authorities.
"In my heart, both of them are there. They are my Buddha. To be honest, both are important, but in my heart the Dalai Lama does have a higher place, and then the Panchen Lama after that. I don't know why. That is just how my heart thinks," the monk said.
In the absence of their spiritual leader, pilgrims are allowed to visit Lhasa's Jokhang Temple, the holiest shrine in Tibet, and see the Dalai Lama's empty throne.
But Alison Reynolds, director of the International Tibet Support Network (ITSN), says Buddhist believers remain wary of authorities.
"Religion in Tibet is subject to strong controls, and these affect people's everyday lives. Sometimes there are periods where it is slightly more relaxed, and people can have photographs of the Dalai Lama in their home and worship freely. But they are always conscious that the situation could change at any time, and it makes the Tibetan people very cautious," Reynolds said.
According to Beijing, Tibet has a population of 2.7 million, 92 percent of whom are Tibetans. However, the London-based Tibet Support Group claim mass immigration by Chinese settlers has reduced the Tibetans to a minority in their homeland, which in turn disenfranchises them from the future political process.
While Beijing maintains strict controls over religion and political expression in Tibet, it has invested billions of dollars in recent years to bring wealth and stability to the region.
A bridge is rising over a dusty riverbed in the shadow of the Potala Palace, the former home of the Dalai Lama in Lhasa. It is part of a $2.4 billion project to build a 1,140-kilometer railway line from outside Tibet into Lhasa.
Beijing says the railway line, much of which will run at an altitude of more than 4,000 meters, will help develop one of the most remote and least developed regions in the world.
The engineer in charge of the bridge project, Wang Weigao, tells Reuters the railway will bring much-needed economic development to the region.
"Once the Tibet line is open, it will be beneficial for Lhasa and the whole Tibet Autonomous Region. It will stimulate the development of Tibet's economy. It will bring a big change for Tibetans and the lives of the people of Lhasa. And I believe it will bring great development," Weigao said.
But Reynolds from the ITSN says there is a long way to go before the lives of the average farmer or herdsman see some benefit from Beijing's policies.
"The Chinese government is currently still engaged in its Western Development project. This includes large-scale programs such as dams, the railway, natural resource extraction. And these are all projects that are designed to consolidate its political control over Tibet. What we are not seeing is the kind of bottom-up, community-led development projects which the Tibetan people really need," Reynolds said.
Reynolds says Tibetans need access to affordable health care and education, which are today largely provided by nongovernmental organizations.
With additional reporting from Reuters.