At the foot of the stunning red-and-white Potala Palace, under the five-star flag, pilgrims prostrate themselves on the ground, falling to their knees, then lie flat on their stomachs.

Monday is the 21st day of the third month in the Tibetan calendar, not an occasion for massive pilgrimages -- which happen on the eighth, 15th and 30th of every month. Still, devout Buddhists are constantly seen, walking clockwise along the major pilgrimage routes around the Potala and Porgor Street near Jokhang Temple.

A crowd of about 5,000 people from all walks of life gathered in front of Potala Palace Monday morning to mark the special date that opened a new chapter in Tibet's history.

"It's a historic date for all the Tibetans," said Qiangba Puncog, chairman of Tibet's regional legislature, while addressing the crowd. "Tibet's peaceful liberation laid a solid foundation for the subsequent democratic reform, building of socialism and the modernization drive."

A grand flag-raising ceremony was held at 10 a.m., with the entire crowd joining in a chorus of the national anthem.

Flowers were then presented at a monument marking Tibet's peaceful liberation in 1951, and the crowd went silent to mourn the heroes who died in the fight for Tibet's liberation, socialism building and economic development.

"It opened a new chapter in Tibet's history...and ushered in a new period of national unity and rapid development," Qiangba said.

Primary school student Dawa Chodron put on a new red scarf for the occasion. "My parents and teacher all say it's a red-letter day," she said. "I'll remember this date."

As the crowd sang the national anthem, all the pilgrims outside the Potala stopped to pay tribute to the flag.

"The quality of our life is so much better than before, and I feel secure and content on my daily pilgrimage," said Deji, a senior citizen from downtown Lhasa.

Tobgye, 66, was excited to witness the flag-raising ceremony. "This flag changed my fate from serf to government official."

Under the former system in Tibet, Tobgye's family were all serfs without personal freedom. His father died young and the family relied on his mother's meager sewing income.

After Tibet's liberation, Tobgye was able to attend school and secure a job at the agriculture and animal husbandry bureau in Shannan Prefecture.

After he retired at 60, his family bought a house in his hometown of Lhasa.

In Beijing, more than 4,000 km from Lhasa, a seminar was held Monday to commemorate Tibet's peaceful liberation and review the region's development over six decades.

The Tibet Daily published an editorial on Monday to hail Tibet's peaceful liberation and six decades of overall development in the plateau region.

"Over 60 years, the Chinese Communist Party has led people of different ethnic groups in Tibet to create one miracle after another on the 'roof of the world,' and to ink a glorious chapter in the advancement of civilization from darkness to sunlight, autarchy to democracy, poverty to wealth and isolation to openness," the editorial said.