Early Tibetan history is not very well known. It is known that during the second century BC, Tibet was occupied by nomadic tribes. During the 7th and 8th centuries Tibet was a strong military empire developed by the King Songsten Gampo. It was during his reign that the first Tibetan alphabet was conceived. It was also in the 7th century when Buddhism came to Tibet. There were struggles between Buddhism and Bonism until Buddhism fully established itself in the 11th century. By 9th Century, thanks to Padmasambhava, during the reign of King Tritsug Detsen, Buddhism and Buddhist monks were very much in evidence all through Tubo. In the persecution period, during the reign of King Darma, Buddhism was dealt a crushing blow. Monks and buddhist texts and Sakyamuni images were burnt and destroyed. A small number of monks managed to survive by fleeing to Kham. By then, the handful of monks were teaching Buddhism in secret. In the 13th century Tsongkhapa, also known as Lozang Drakpa, was born, in the reign of Yuan Emperor Shundi, at Tsongkha near the city of Xining in Qinghai Province. He became a monk at age seven. At 17 years of age, the fifth year of Ming Emperor Taizu's reign, he went to Tibet to study Buddhist philosophy. By the age of 29, Tsongkhapa took his gelong vows before Tsutrim Richen at the Namgyal Monastery in Yarlung. Some 16 years later, Tsongkhapa began to write the scriptures of the Yellow Sect. In the early 14th century Tsongkhapa started the Monlam Festrival of prayer and giving of alms. In 1419 Tsongkhapa died, (first Abbot of Ganden), at age 63, during the reign of Ming Emperor Chengzu. His topmost disciple Gyaltsub Je succeeded him as the second Abbot of Ganden. There are 4 schools of Tibetan Buddhism. The oldest school or "form" of Tibetan Buddhism is the Nyingma(meaning "Ancient Ones"). It is based on a lineage of teachings and traditions introduced during the reigns of the Buddhist Kings of the Yarlong Dynasty in the eighth and ninth century by Padmasambhava, Shantarakshita, Vilalamitra, and others. Then there is the Kagyu ( 'Oral Lineage' )school. The particular feature of the Kagyu lineage is that the teacher, after having mastered the teachings, clears away defects - relating to intellectual understanding, meditational experience, and the various levels of realisation. Upon completion of the process, the teacher is able to point out and introduce mahamudra to the disciple. The Kagyu teachings have been transmitted and preserved this way, in an unbroken line, until the present time. Then we have the Sakya ( or 'Grey Earth') tradition. The Sakya tradition originated in the eleventh century, and has been closely associated with the Khon Family. Khon Lui Wangpo Sungwa became a disciple of Guru Rinpoche in the eighth century. Through the next thirteen generations, the Dharma continued to be propagated through the Khon family. In 1073, Sakya Monastery was built by Khon Konchok Gyalpo which established the Sakya Tradition in Tibet. He studied under Drokmi the Translator (992-1072) and became a master of many deep teachings. And last but not least we have the Gelug (meaning: 'Way of Virtue') tradition. This is lineage combines the teachings and practices of the Nyingma, Kagyu and Sakya with the Sutra and Tantra systems of Indian Buddhism and the intellectual heritage of Nagarjuna and Asanga. It was founded by Gyalwa Tsongkhapa (1357-1419) Tsongkhapa's disciple, Gyalwa Gedun Drupa was the first of the fourteen successive rebirths of the Dalai Lama. The present Dalai Lama is Tenzin Gyatso, known to his followers as Vajradhara Vagindra Sumati Shasana Dhara Samudra Shri Bhadra. He was given the Nobel Peace Prize in 1989 in recognition of his tireless efforts on behalf of world peace and alleviating the sufferings of the Tibetan people under the genicidal policies of the Chinese government. It is also important to note two other Tibetan schools here briefly, The Kadam School and Rime School. The Kadam School was founded by the eleventh century century Indian scholar and saint Atisha and his Tibetan disciple Dromtonpa. This school is particularly known for its great emphasis on practical application of the ideals of a Bodhisattva within the practitioner's daily life and is responsible for the development in Tibet of a specific collection of writings known as Lojong or "Thought Transformation". The Kadam school later evolved into three sub-divisions Lamrimpa, Shungpawa, and Mengapa, each founded by one of the three Kadam brothers, whose names were Potowa, Chekawa, and Phuljungwa. Although there is no existing school of Tibetan Buddhism now explicitly known as Kadam, the teachings in this school are highly respected by all the four major traditions, and in particular by the Gelug school, which is also sometimes known as the "new Kadam" school. The Rime School is a non-sectarian or eclectic movement which crystallized during the nineteenth century in Eastern Tibet where the study and integration of all schools of Tibetan Buddhism were encouraged by the leading figures of that time, namely: Jamyang Khyentse Wangpo, Jamgon Kongtrul Lodro Thaye, Chogyur Dechen Lingpa, and Ju Mipham Gyatso. A principal feature of the Rime movement was the emergence of a new literature. This consisted primarily of compendiums of major works of all the major and minor schools of Tibetan Buddhism on convergent topics of thought and practice.