By 100 BCE
Aṅguttaranikāya mentions the luminous nature of the mind.
By 100 CE
Mahāparinirvāṇasūtra (which Michael Radich dates as early as the 2nd century) mentions tathāgathagarbha and uses the term ātman to describe buddha-nature.
c. 200 CE
Tathāgatagarbhasūtra (as dated by Michael Zimmermann) and other scriptures later considered as sūtras teaching tathāgathagarbha are circulating and promoting the concept of buddha-nature.
c. 200 CE
Nāgārjuna writes the Dharmadhātustava and praises the sphere of reality as the basis of saṃsāra and nirvāṇa. He calls it "the element" and "luminous mind" and claims emptiness does not negate this nature.
c. 300 CE
c. 320 CE
Śrīmālādevīsiṃhanādanirdeśa (which may have been circulating as one of the most influential sūtras on buddha-nature) is said to have been translated into Chinese by Seng Fani. It claims buddha-nature "is empty of adventitious stains but not empty of its limitless inseparable qualities."
By 400 CE
Mahābherīsūtra (which was translated into Chinese by Guṇabhadra) equates buddha-nature with the dharmakāya. Anūnatvāpūrṇatvanirdeśaparivarta (which Jonathan Silk dates to at least before the early 5th century) mentions how sentient beings, bodhisattvas, and buddhas are three phases of the buddha-nature being impure, partially obscured, and fully pure.
By 433 CE
According to Takasaki, the Ratnagotravibhāga, which Central Asian and Tibetan sources attribute to Maitreya and Chinese sources attribute to Sāramati, is composed.
c. 500 CE
c. 550 CE
Paramārtha translates the Awakening of Faith attributed to Aśvaghoṣa into Chinese and thereby promotes the concept of Original Enlightenment.
Tanyan writes the first commentary on the Awakening of Faith, which was followed by some 170 other commentaries written in China, Japan, and Korea.
The Great Samye Debate takes place between the Indian gradualists led by the Mādhyamika master Kamalaśīla and Chinese subitists led by Chan monk Heshang Moheyan (or Hashang Mahāyāna).
c. 800 CE
Yeshe De and others translate major buddha-nature sūtras such as the Tathāgatagarbhasūtra and Mahāparinirvāṇasūtra into Tibetan.
By 1040 CE
Maitrīpa (986-1063) is said to have discovered the texts of the Ratnagotravibhāga and Dharmadharmatāvibhāga in a stūpa.
c. 1045 CE
Ratnavajra, grandfather of Sajjana, is believed to have composed his commentary on the Ultimate Continuum.
c. 1050 CE
Atiśa Dīpaṅkara and Naktso Tsultrim Gyelwa translate the Ratnagotravibhāgauttaratantra or the Ultimate Continuum into Tibetan in Yerpa, Tibet.
Ngok Loden Sherab and Tsen Khawoche depart for Kashmir where they would receive teachings on the works of Maitreya, including the Ultimate Continuum, from Sajjana.
c. 1085 CE
Tsen Khawoche Drime Sherab, who received teachings on the Ultimate Continuum from Sajjana with the help of Zu Gawai Dorje as translator, returns to Tibet and teaches the Ultimate Continuum, thereby starting the meditative tradition (སྒོམ་ལུགས་) of the Ultimate Continuum.
By 1092 CE
Ngok Loden Sherab translates the Ultimate Continuum with the help of Sajjana in the town of Anupama in Kashmir. He also composes his commentaries on the Ultimate Continuum, and Sajjana writes his instructions on the Ultimate Continuum.
c. 1100 CE
Marpa Dopa Chökyi Wangchuk composes his commentary on the Ultimate Continuum according to his teacher Parahita's explanation, although the commentary is perhaps mistakenly attributed to Marpa Chökyi Lodrö.
c. 1100 CE
Patsab Lotsāwa Nyima Drakpa, who introduced the Prāsaṅgika Madhyamaka tradition to Tibet, and Marpa Dopa Chökyi Wangchuk, who is known for the transmission of Cakrasaṃvara to Tibet, translate the Ultimate Continuum. Marpa Dopa also composes his commentary.
c. 1130 CE
c. 1150 CE
Chapa Chökyi Senge, the sixth abbot of Sangpu Neutok, composes his summary as well as a detailed explanation of the Ultimate Continuum and carries on the philosophical legacy of Ngok Loden Sherab.
c. 1150 CE
Lhodrak Dharma Senge, for whom we do not have much information, composes his commentary on the Ultimate Continuum.
Drogön Chögyal Pakpa writes his synopsis of the Ultimate Continuum in the palace of Kubilai Khan in China.
c. 1200 CE
Jetsun Drakpa Gyaltsen composes his notes on the Ultimate Continuum entitled the Unmistaken Intent of Maitreya in response to master Thinley Zangpo.
Sherab Jungne, the student of Jikten Gönpo Rinchen Pel of Drigung, compiles the Single Intention containing the 150 vajra statements of his master, thus launching an important classic of the Drigung Kagyu school.
c. 1230 CE
Sakya Paṇḍita Kunga Gyaltsen critiques the other theories of buddha-nature and presents buddha-nature as an unchanging sphere of reality in his Distinguishing the Three Vows. He argues that the buddha-nature sūtras teaching innate enlightenment are provisional teachings.
c. 1270 CE
Kyotön Mönlam Tsultrim, the eighth abbot of Nartang, composes many works on buddha-nature, including his Instructions on "The Ultimate Continuum of the Mahāyāna", and he promotes the meditative tradition from Tsen Khawoche.
c. 1280 CE
Chomden Rikpai Raldri, a learned Kadam scholar of Nartang, writes his exegesis on the Ultimate Continuum entitled the Ornamental Flower and also writes his History of Dharma Associated with Maitreya.
c. 1300 CE
Lodrö Tsungme of Sangpu Neutok composes his commentary on the Ultimate Continuum entitled The Precious Lamp That Illuminates the Definitive Meaning of the Mahāyāna Uttaratantra Treatise, which is aligned to the interpretation in the meditative tradition.
c. 1300 CE
One Yarlung Lotsāwa, according to Gö Lotsāwa Zhönu Pal, is said to have translated the Ultimate Continuum.
c. 1320 CE
The Third Karmapa Rangjung Dorje composes his Treatise on Pointing Out the Tathāgata Heart, a commentary on the Dharmadhātustava, and other writings related to buddha-nature.
Tanak Rinchen Yeshe, who was a teacher of both Tokme Zangpo and Dolpopa, writes his Illumination of the Definitive Meaning: A Commentary on the Uttaratantra in Relation to the Sūtras, which presents a proto-zhentong interpretation.
By 1333 CE
Dolpopa Sherab Gyaltsen writes his tour de force Mountain Doctrine and many other works and he expounds the philosophy of zhentong or "other-emptiness," in which conventional phenomena are empty of self-existence and buddha-nature is the ultimate absolute reality endowed with all qualities of the Buddha.
c. 1350 CE
Longchenpa Drime Õzer composes his Seven Treasures, Trilogy of Relaxation, and Trilogy of Liberation, in which he presents buddha-nature as the empty luminous nature of the mind.
c. 1350 CE
Sazang Mati Paṇchen Lodrö Gyaltsen improves the Tibetan translation of the Ultimate Continuum and writes his long and clear exposition Illuminating the Definitive Meaning: An Explanation of the Ultimate Continuum.
c. 1350 CE
Zhangtön Sönam Drakpa, a student of Dolpopa, writes his Commentary on the Ultimate Continuum Clarifying the Last Wheel of Teachings, highlighting how the third turning is a definitive teaching.
c. 1350 CE
Gyalse Tokme Zangpo writes his commentary on the Ultimate Continuum, Illuminating the Definitive Meaning, in E temple.
Butön Rinchen Drup writes his Ornament That Illuminates and Beautifies the Tathāgata Heart and underscores that the buddha-nature teachings are expedient provisional teachings and not to be taken literally.
c. 1360 CE
Dondrup Rinchen, the first teacher of Tsongkhapa, composes his commentary on the Ultimate Continuum, in which he refutes certain interpretations of buddha-nature which were later adopted by the Geluk tradition.
Lama Dampa Sönam Gyaltsen composes his commentary on the Ultimate Continuum entitled Definitive Clarification of the Intent, with Gyeltsen Zangpo as scribe. A synopsis containing a topical outline was also extracted later. He presents an interpretation different from the position of Sapañ.
c. 1380 CE
Yeshe Dorje from Minyak, a student of 4th Karmapa Rolpai Dorje and Donzhak (Mase Tönpa Rinchen Zangpo), writes his commentary on the Ultimate Continuum highlighting the zhentong view.
c. 1385 CE
Rendawa Zhönu Lodrö, the great promoter of Mādhyamika in Tibet, composes his synopsis on buddha-nature and exegesis on Kālacakra, highlighting the rangtong understanding, although Gö Lotsāwa claims that he later changed his approach.
Gharungpa Lhai Gyaltsen writes his commentary on the Ultimate Continuum in Namkha Dzod hermitage following Dolpopa's zhentong tradition and Sazang's outline.
c. 1390 CE
Gendun Özer, a Kadampa master who is difficult to date, composes his outline and commentary on the Ultimate Continuum, claiming it to be different from the wordy commentaries from the past and presenting logical arguments, direct explanation, enumeration, etc., as requested by his students in central Tibet. He uses Ngok's translation but uses Naktso and Patsap's translation also.
c. 1400 CE
Tsongkhapa Lobzang Drakpa, who founded Ganden monastery in 1409, writes his Great Treatise on the Stages of the Path to Enlightenment followed by other works which initiated the Geluk understanding of buddha-nature.
c. 1420 CE
Gyaltsap Darma Rinchen, who received teachings on the Ultimate Continuum from both Rendawa and Tsongkhapa, writes his commentary on the Ultimate Continuum, which came to influence the subsequent Gelukpa understanding of buddha-nature and its interpretation of the Ultimate Continuum. The commentary was written at Nenying at the request of Gungru Gyaltsen Zangpo.
c. 1425 CE
By 1450 CE
Bodong Paṇchen Chokle Namgyal writes his commentary on the Ultimate Continuum and presents an interesting interpretation.
The 7th Ganden Tripa Lodrö Tenpa writes his commentary on the 'Ultimate Continuum following the interpretation of buddha-nature by his master Gyaltsap Je.
Gö Lotsāwa Zhönu Pal, the famous historian, dictates his extensive commentary on the Ultimate Continuum in Mondang.
Śākya Chokden composes his Explanation of Buddhagarbha: An Essence of Sūtra and Tantra, highlighting his position that real buddha-nature does not exist in sentient beings.
The Karma Kagyu scholar Dumowa Tashi Özer, a student of the 7th Karmapa, writes his commentary on the Ultimate Continuum, integrating the points from the 3rd Karmapa Rangjung Dorje's synopsis.
Paṇchen Sönam Drakpa, the main author studied in Drepung Loseling, composes his commentary on the Ultimate Continuum based on Gyaltsap Je's commentary at Gaden Zurkhang.
c. 1550 CE
The Eighth Karmapa Mikyö Dorje writes his The Lamp That Excellently Elucidates the System of the Proponents of the Other-Emptiness Madhyamaka and other works and highlights the understanding of "expanse zhentong."
c. 1615 CE
Tāranātha writes many works, including his masterpiece Thoroughly Ascertaining the Great Middle Way of the Expansive Supreme Vehicle and championed the zhentong philosophy of Jonang tradition.
c. 1620 CE
One Taklung Chöje, perhaps Taklung Zhabdrung Ngawang Namgyal, composes his commentary on the Ultimate Continuum, in which he refutes various Tibetan interpretations.
c. 1670 CE
Tsele Natsok Rangdrol, a Drukpa Kagyu master, writes his treatise on understanding buddha-nature and ultimate reality in the context of Madhyamaka, Mahāmudrā and Dzogchen, particularly relating it to practical application.
c. 1820 CE
Getse Mahāpaṇḍita Tsewang Chokdrup, a leading Nyingma master from Kaḥthog monastery, writes his exegesis on buddha-nature and the Great Middle Way, highlighting the validity of zhentong.
c. 1851 CE
The itinerant monk scholar Dza Patrul Rinpoche composes his topical outline of the Ultimate Continuum in Zamthang monastery.
c. 1880 CE
Jamyang Khyentse Wangpo, a leading rime master, writes his quintessential presentation of the zhentong philosophy in the Jonang tradition.
By 1899 CE
Jamgön Kongtrul Lodrö Taye writes his experiential commentary on the Ultimate Continuum, in which he presents the understanding of other emptiness.
Mipam Namgyal Gyatso, the 19th century Nyingma polymath, writes his exegesis on buddha-nature called Lion's Roar and underscores his understanding of buddha-nature as a union of emptiness and luminosity. He also makes an annotated commentary to the Ultimate Continuum which his students compiled in 1925.
c. 1900 CE
Khenpo Zhenpen Chokyi Nangwa, also known as Zhenga, composes his interlinear commentary on the Ultimate Continuum as part of the thirteen great treatises, which came to be widely used in shedra curricula.
c. 1910 CE
Drakar Lobzang Palden Tendzin Nyendrak writes his commentary on the Ultimate Continuum following Gyaltsap Je's interpretation and also his work on zhentong on behalf of some monks of Zamtang.
c. 1930 CE
Ngawang Tsoknyi Gyatso, a Jonang scholar of Zamtang monastery, writes his treatises on buddha-nature explaining the zhentong tradition of Dolpopa, although Michael Sheehy considers his understanding lenient and mild zhentong.
Eugène Obermiller translates the Ultimate Continuum for the first time into English in his The Sublime Science of the Great Vehicle to Salvation, Being a Manual of Buddhist Monism: The Work of Ārya Maitreya with a Commentary by Āryāsanga.
Ngawang Lodrö Drakpa writes his Fearless Lion's Roar, also known as the Great Zhentong Which Highlights the Zhentong Tradition of Jonang. The book came to be a classic on zhentong alongside Dolpopa's Mountain Doctrine and Tāranātha's Thoroughly Ascertaining the Great Middle Way of the Expansive Supreme Vehicle.
David Seyfort Ruegg articulates and analyzes the theories on buddha-nature in his La théorie du tathagatagarbha et du gotra: Études sur la sotériologie et la gnoséologie du Bouddhisme.
Jangtse Khenzur Sönam Kunga finishes his compilation of the various Tibetan philosophical understandings and interpretations of buddha-nature in Sarnath.
c. 1990 CE
Muge Samten Gyatso composes his commentary on the Ultimate Continuum as requested by one Lobzang Tashi, but the commentary is incomplete due to his illness.
The Gelukpa scholar Yeshe Gyatso of Chentsa Mani temple in Qinghai wrote his summary of, which is a full commentary on, the Ultimate Continuum following Gyaltsap Je's interpretation.
Troru Tsenam completes his commentary on the Ultimate Continuum, which is based on the transcription of his lectures.
Kazuo Kano completes his dissertation on "rNgog Blo-ldan-shes-rab's Summary of the Ratnagotravibhāga: The First Tibetan Commentary on a Crucial Source for the Buddha-Nature Doctrine," at the University of Hamburg. Later published as Buddha-Nature and Emptiness.
The 7th Drikung Chetsang, Konchog Tenzin Kunsang Thrinle Lhundrup, composes his commentary on the Ultimate Continuum entitled Words of Asaṅga.
Karl Brunnholzl produces his tour de force on buddha-nature When the Clouds Part: The Uttaratantra and Its Meditative Tradition as a Bridge between Sutra and Tantra and highlights the zhentong tradition.
Tsering Wangchuk publishes his historical account of buddha-nature scholarship in Tibet entitled The Uttaratantra in the Land of Snows: Tibetan Thinkers Debate the Centrality of the Buddha-Nature Treatise.
Tsadra Foundation's web resource on buddha-nature launches followed by a series of monthly discussions called Conversations on Buddha-Nature.