Sakyasribhadra, also known as Sakyasri or Khache Panchen, was an important Kashmiri pandita in the 12th and early 13th centuries who came to Tibet. His full biography is on the Treasury of Lives site. He has a connection with many of the lineages in Tibet extant during his visit.
Sakyasribhadra: A Reader's Guide to the 12th Century Kashmiri Pandita
He is well known in the Sakya tradtion for being one of Sakya Pandita's teachers. Together they translated Dharmakirti's Pramanavarttika which Saypan then taught extensively.
As described in both Parting from the Four Attachments: A Commentary on Jetsun Drakpa Gyaltsen's Song of Experience on Mind Training and the View and Treasures of the Sakya Lineage, Jetsun Dragpa Gyaltsen, Sakya Pandtia's uncle was practicing so Saypan and Sakyasribhadra went to see him:
"Jetsun Rinpoche was making the offerings and praises to the Guhyasamaja deity he had created in front of him. Thinking he should show respect to his visitor, he rose to greet the Pandita, intended to place his bell and vajra on the table but leaving them hanging in the air.
The great Pandita said, 'That is really a cause for amazement.'
Jetsun Rinpoche humbly replied, 'This is nothing amazing at all.'
The Pandita then prostrated to Jetsun Rinpoche, but the junior panditas with him complained, saying 'It is not appropriate to offer prostrations to a layperson. Even though you did it already, please do not offer him more.'
The great Pandita replied, 'Jetsun Dragpa Gyaltsen is the true Mahavajradhara. He has seen the mandala of Guhyasamaja.' He then made Jestun Rinpoche his crown ornament."
Later, according to Ringu Tulku's The Ri-Me Philosophy of Jamgon Kongtrul, Sakyasribharda gave Vajrikilaya instrucitions to Jetsun Drakpa Gyaltsen.
This work discusses Sakyasribhadra several times, including how he brought a Kalachakra teaching lineage to Tibet, now referred to as Panchen Luk or Chal Luk.
When the Clouds Part: The Uttaratantra and Its Meditative Tradition as a Bridge between Sutra and Tantra mentions him several times, once in an account from Go Lotsawa's Blue Annals of Sakyasribhadra giving pith instruction on the five works of Maitreya, and a brief discussion of his Mahamudra transmissions.
He is known for establishing an ordination lineage of the Vinaya in western Tibet after the dark period following King Langdarma. Sakyasribhadra also introduced a new way of approaching Buddhist chronology, different from what had come into Tibet previously but closer to what we know today from scholarly research. He is also associated with a teaching lineage on the Treasury of Abhidharma.
He is also connected with the Drikung Kagyu tradition and Jigten Sumgon. This is detailed in several sections on Opening the Treasure of the Profound: Teachings on the Songs of Jigten Sumgon and Milarepa. Here is one of them, translated from Pemap Karpo:
"An arhat from Ceylon gave three golden flowers to Khache Panchen and asked him to take them to Tibet. He said that one should be given to the incarnation of Arya Nagarjuna, but Khache Panchen didn’t know where to find him. When Khache Panchen was staying at Lemoche, he announced that whoever came to him for bhikshu ordination would receive a Dharma robe. A Khampa monk from Drigung received ordination and asked for a robe, but none were left. He insisted, and tugged at the robe of Khache Panchen. Khache Panchen’s attendants beat him, and blood flowed from his mouth and nose.
Ordinarily, White Tara would appear in Khache Panchen’s meditation, but for seven days after that incident she didn’t show herself. Khache Panchen did purification practices and supplicated her. After seven days had passed, Tara appeared with her back turned to him. 'Arya Tara,' he asked, 'what have I done wrong?' She replied, 'You defiled your karma by beating Nagarjuna’s disciple.' 'I don’t remember that,' he said, and Tara answered, 'You beat him until he bled.' Khache Panchen asked how he could purify that misdeed, and Tara replied, 'You should give Dharma robes equal in number to your years to those monks who have none.' He promised to do that, and then searched for the monk who had been beaten. He found him, learned the name of his teacher, and realized that Jigten Sumgön was Nagarjuna. He offered the flower to him."
For the Nyingma tradition he was a supporter, reporting the existence of both the Guhyagarbha tantra-which he saw with his own eyes in Sanskrit at Samye- as well as the extant practice of Varjakiliaya in India, both of which had come under some doubt in some quarters as not having confirmed Indian origins.
Jamgon Kongtul Lodro Thaye, in his Autobigraphy recounts several appearances of Khache Panchen including this dream:
"One night, I dreamed of a temple in the Indian style, with a courtyard surrounded by a low brick wall. Off to one side, I saw an image of the great glorious Vajrakumara, in a style resembling the Nepalese, which I understood to be painted by Khaché Panchen in blood that flowed from his own nose. To either side of the figure, the canvas was filled with depictions of the essential mantra of the deity. This image became more and more radiant, until finally I couldn’t bear to look at it."
There is an out-of-print book by David Jackson, Two Biographies of Sakyasribhadra, (there were five but the other three are lost) a review of which is available on Academia.edu.
For those with access, the Journal of the American Oriental Society, vol. 114, has Leonard van der Kuijp's "On the Lives of Sakyasribhadra".
Lotsawa House has several pieces of has work translated including Instructions on Pure View and Conduct, A Brief Practice for Paying Homage and Making Offerings to the Buddha Together with his Retinue of Arhats, and The Seven Branches for Practicing the Sacred Dharma (which includes a common refuge prayer).