The Buddhist Gagyu Sect has exerted great influence on Tibetan history. In Tibetan, "Ga" means " statement of the Buddha" and " gyu"  means " carry forward" . Major masters of the Gagyu Sect included Marba, Milha Riba, Riqoinba and Linqenriba.

During his three visits to India, Marba translated and brought back to Tibet some of the Tantric classics. He recruited students and lectured on Tantric philosophy. His school was called Bagagyu. As it was formed in Tabolagyi, the school was also called Tabogagyu.
Qoinbu Nanjor visited India many times. Upon his return home, he created the Shangbagagyu Sect. But this was no match for the Tabogagyu Sect in terms of disciples and influence, so what people call the Gagyu Sect refers mainly to the latter.

There is a poem that states: " Marba experienced hardships to visit India, where he invited four Buddhist classics to the snowland; Milha Riba practiced Buddhism very hard; and Tabo spread the religious seeds far and wide." 

Marba was one of the four major sutra translators. He founded the Gagyu Sect. Milha Riba was one of his four major disciples. Tabolhagyi was a disciple of Milha Riba. He managed to combine the tenets of the open and secret schools of the Gadain Sect with the Tantric doctrines to create the Tabogagyu Sect, which featured both theory and practice. Thanks to the efforts of the three masters, the Gagyu Sect was able to expand its influence in the short span of 100 years.

Tabolhagyi had four major disciples-Duisum Qenba, Shanchaiba, Darma Wangqug, and Dorje Gyibo. All of them managed to build monasteries and attract disciples, forming the eight sub-sects known as Zhigung, Dalung, Zhuba, Yasang, Chopu, Xiusai, Yeba, and Macang. Hence, the Gagyu Sect is often mentioned as the " Four Large and Eight Minor."

The Gagyu Sect became so influential that, in 1239, when the Mongolian General Dordanapo reached Tibet, he made a report to Prince Godan saying: " The Gadang Sect has more monasteries than any others. The Prince of Dharma Dalung has a good knowledge, but Master Jinwo with the Zhigung Sect possesses superb magic powers. Sagya Pandit is knowledgeable."  From this, we see that the Sagya Sect was famous for its eminent monks and people with great influence.

Of the 13 wanhu (10,000-household) offices set up during the Yuan Dynasty, the top three were-Zhigung, Chaiba and Pagmo Zhuba. In 1354, the Pagmo Zhuba overthrew the Sagya regime and ruled Tibet for 264 years.

During the Ming Dynasty, the Central Government bestowed honorific titles on three Princes of Dharma and five Princes. Of the three Princes of Dharma, the 5th Deyin Xieba with the Garma Gagyu’s Black Hat took first place. Of the five Princes, two were with the Gagyu Sect.

It relied closely on the local government for expansion. It quickly spread to all parts of Tibet, from Qamdo in the east to Ngari in the west, and even covered present-day western Sichuan, northern Yunnan, Ningxia and Inner Mongolia. It also made its way into Nepal, Sikkim, Kashmir and Bhutan. In the late 1950s, there were people who spread the doctrines of the Gagyu Sect in Europe and the United States.

The Sagya Sect also contributed to Tibetan culture. Eminent monks contributed to the compilation of the Red Annals, Blue Annals, A Feast to Scholars, Biography of Master Translator Marba, Biography of Milha Riba and His Philosophy, and Tangdong Gyibo. Ancient Tibetan opera is closely related to the Gagyu Sect in many ways; the sect's holy dance is unique; and the Zhigung Celestial Burial Field is one of the three largest ones in the world. The Living Buddha incarnation system, still followed today, was initiated by the Gagyu Sect.

In a nutshell, the Gagyu Sect holds an important place in the Tibetan history.