The Sera, Gadan and Drepung Monasteries are known as the 3 great monasteries of Tibet. All belonging to the lineage of Gelugpa started by Je Tsong Khapa in early 15th century and all are within Lhasa, capital of Tibet. Contrary to common understanding, these great monasteries are not places of worship and rituals but are in reality monastic universities providing religious education to the monks from age 8 to up to 70 in some cases.
Though Gadan monastery is the spiritual head quarter of the lineage, it was the Drepung monastery that has the highest number of monks in the past, before the political changes took place in Tibet. Drepung used to have 7,700 monks, Sera 5,500 and Gadan 3,300. These are the official numbers but the actual numbers of monks have often exceeded these numbers in the history. Drepung at its peak hosted over 10,000 monks. Sera-Je, just one of the 3 Colleges of Sera Monastery, hosted over 6,000 between the 1930's and 1950's.
Each monastery has its own syllabus and monastic rules, besides the common monastic rules as prescribed by the Buddha for monasteries. Here is a rough description of different aspects of Sera Monastery before communist time. The other 2 monasteries would have their own unique characteristics in some aspects but the main description would be the same for them otherwise.
Sera was established by Jamchen Choje Sakya Yeshe in 1419 on the request of his teacher Je Tsong Khapa. Sakya Yeshe was the close disciple of Tsong Khapa who was invited to become mentor of the Chinese emperor on behalf of Tsong Khapa and who taught extensively in China, particularly in the Imperial court, converting many royal members and in Wutaisan. He was one of Lama Tsong Khapa's 8 close disciples who were known as the eight flagpoles upholding the teachings. When he returned to Lhasa from China, he bought along gifts from the emperor, including a set of Tangyur (canons of teachings spoken by Buddha) commissioned by the emperor, a set of 16 arhats, a sandalwood statue of the Buddha. These became the treasures of Sera, along with a Hayagriva statue said to have once spoken and a Chenrezig statue which belonged to the famous nun, Gelongma Padma, lineage founder of the set of 11 faced Chenrezig practices including the Nyunglay practice, transmitted directly by Chenrezig to the nun in a vision.
There is a beautiful story related to the set of Tangyur texts. When Sakya Yeshe returned from China, there has been an accident and the texts granted by the emperor felt into a big river as he crossed it. He thought the texts were lost and carried on the journey. Before his return however, an old man with attendants came to Sera and presented the set to the monastery and said that he was delivering it for Sakya Yeshe.
Upon being told the story later, Sakya Yeshe examined the texts and found that they were still not completely dried and it was believed that the old man was a Naga (water spirit) king. There is another story relating to another set of canons kept at Sera as monastic treasures. A monk once prayed very sincerely in front of a statue that one day he would be able to afford to commission the printing of a wood block set of texts. The next day he found a mysteriously appeared full set of ink, blocks and paper underneath the altar and printed this set of texts, which was presented to Sera. This set is known as 'the mysteriously appeared canon'. Most of the treasures listed above are still being preserved at Sera today.
Sera Choding, where Tsong Khapa did retreats
Of the 3 great monasteries, Sera is the closest to the Potala Palace at Lhasa and is 3 kilometers away from it. The entire monastic complex occupied 2 square kilometers. The rock formations behind the monastery bear close resemblance of the 8 auspicious symbols. Behind Sera, there is the Choding hermitage where Je Tsong Khapa lived and retreated and composed many important texts. There is also a throne where he used to teach and next to it there is a small spring sacred to White Manjusri. It is believed that the spring water is good for healing stomach ulcers and for improving wisdom.
Higher up the hill, there is a house where Marpa's handprint could be seen. A few kilometers away is the Pabongkha palace, which was a retreat used by the Tibetan king Songtsen Gonpo and his 2 wives. It was here that Thomi Sambhota invented Tibetan at the request of the king, using Sanskrit as the blueprint. As he came out of the retreat, people gathering at this house asked him to demonstrate his works and the newly invented written language. He wrote on the wall in Tibetan the mantra of the Buddha of Compassion, Om Mani Padme Hum, and it has become the first use of the Tibetan language. To this day, the mantra could be seen.
At the foot of this house, there is a natural pattern of an eye on a rock. This is said to be one of the 3 Dakini eyes which could be seen around this area. The house was also made famous by its later resident, Pabongkha Rinpoche. Not far from the house is the Pabhongkha cave which is said to be a holy place of the Dakinis. A natural pattern of an eye (second of the 3 eyes) could be seen in the cave and on the roof there is a natural pattern of a triangular 'Dharma source'. Pabongkha Rinpoche spent most of his days in this cave retreating.
The monastery comprises two independently functioning colleges, Sera-Je and Sera-Mey. Sera Mey was first established in Tibet in 1421 by Kunkyen Jangchub Boompa, also a disciple of Je Tsong Khapa. Over the centuries the monastery has produced many great scholars. Until 1959 the college housed nearly 5,000 monks.