Chaitanya Mahaprabhu was a 15th-century Indian saint who is considered to be the combined avatar of Radha and Krishna by his disciples and various scriptures. He was born as Vishvambhar Mishra in Nabadwip, West Bengal, to Brahmin parents. Chaitanya is known for his mode of worshipping Krishna with ecstatic song and dance, which had a profound effect on Vaishnavism in Bengal. He founded Gaudiya Vaishnavism and expounded Bhakti yoga, popularizing the chanting of the Hare Krishna Maha-mantra.

Chaitanya met his guru, the ascetic Ishvara Puri, when he was travelling to Gaya to perform the Śrāddha ceremony for his departed father. Upon his return to Bengal, he became the eminent leader of the Vaishnavas in Nadia. He later received entrance into the sannyasa order by Swami Kesava Bharati and travelled throughout India, chanting the divine names of Krishna constantly. He spent the last 24 years of his life in Puri, Odisha, where he is believed by his followers to have sunk deep into various Divine-Love trances (samādhi) and performed pastimes of divine ecstasy (bhakti).

Chaitanya is also known for his visit to Vrindavan, the land of Radha Rani and the “City of Temples”. In the year 1515, he visited Vrindavan with the purpose of locating the lost holy places associated with Krishna's transcendent pastimes. By his divine spiritual power, he was able to locate all the important places of Krishna's pastimes in and around Vrindavan, including the seven main temples or sapta devalay, which are worshiped by Vaishnavas in the Chaitanya tradition to this day.

There are several biographies available from the time that provide details of Chaitanya's life. The most prominent among them are the Chaitanya Charitamrita by Krishnadasa Kaviraja and the Chaitanya Bhagavata by Vrindavana Dasa, both originally written in Bengali but now widely available in English and other languages. Additionally, there is the Chaitanya Mangala by Lochana Dasa, also written in Bengali with Sanskrit verses interspersed. Chaitanya's contemporaries also composed other Sanskrit biographies, such as the Caitanya Caritāmṛta Mahākavya by Kavi Karnapura and Śrī Kṛṣṇa Caitanya Carita Maha-Kavya by Murari Gupta.

Works on Chaitanya:

Krsna-Caitanya-Caritamrta (c. 1513 or 1536–1540; Sanskrit)
By Murari Gupta. Known as a kadcha or chronicle. Chaitanya's Navadwipa līla and each panca-tattva presented as a form of the Lord. Caitanya went for the first time to Murari's house at Navadwipa. Murari's standing and reputation for learning gave his biographical materials great weight in the Vaishnava community. This Kadcha (notes) became the guiding lines for other biographers.
Kadcha or chronicle (Sanskrit)
By Svarupa Damodara. He was the personal secretary of Chaitanya. Details the life of Caitanya.
Govindadaser Kadcha (Bengali)
By Govinda Dāsa who accompanied Chaitanya on his tour of Deccan. This poem describes their experiences on the journey and some imaginary events in the life of Chaitanya as well as his ideas and philosophy. It is another significant biographical work, but it was regarded as controversial because of the authenticity.
Chaitanya Bhagavata (c. 1535 or 1546–1550; Bengali)
By Vrindavana Dasa Thakura. Three parts: Adi-Khanda, Mādhya-Khanda, and Antya-Khanda. Chaitanya's earlier life, activities, early movement in Navadwip.
Krsna-Caitanya-caritra-mahakavya (c. 1535)
By Kavi Karnapura (Paramanand Sen).
Krsna-Caitanya-candrodaya-natakam (c. 1535 – 1570s)
By Kavi Karnapura. Based on Murari Gupta's Krsna-Caitanya-Caritamrta. When Karnapura was a small child, he interacted with Chaitanya personally.
Caitanya-candrodaya-natakam (c. 1538 or 1540 or 1572 or 1579; Sanskrit)
By Kavi Karnapura (Paramanand Sen). Dramatic play in ten acts of Chaitanya's life.
Caitanya-caritāmṛta-kavya (c. 1542 – late 1500s; Sanskrit)
By Kavi Karnapura (Paramanand Sen). A long biographical poem on Chaitanya's life and acts.
Caitanya-caritāmṛta (c. 1557 or 1580 or 1615; Bengali)
By Krishnadasa Kaviraja. Three parts: Adi-lila, Madhya-lila, and Antya-lila. Massive authoritative composition of Chaitanya's biography and teachings. According to Manring, he draws liberally from previous writers (poets, theologians and biographers) as he deems correct, omitting Kavi Karnapura's works perceived as threatening Rupa's authority.
Caitanya-Mangala (c. 1560 or late 1500s; Bengali)
By Jayananda. Nine parts: Adikhanda, Nadiyakhanda, Vairagyakhanda, Sannyaskhanda, Utkalkhanda, Prakashkhanda, Tirthakhanda, Vijaykhanda, and Uttarkhanda. Biographical poem in the form of a narrative play focused on Chaitanya's godly image. It is the only work in which his death is mentioned. Introduction mentions several previous biographers, of whom only Vrindavan is known. Written for the common people (not devotees).
Chaitanya Mangala (c. 1560–66 or 1575)
By Lochana Dasa (a.k.a. Trilocan Dasa). Four parts: Sutrakhanda, Adikhanda, Madhyakhanda, and Antyakhanda. A narrative play depicting Chaitanya's childhood activities and his human side without highlighting any divine matters to make it popular. Influenced by Murari Gupta's Krsna-Caitanya-Caritamrta and Vrindavana Dasa Thakura's Chaitanya Bhagavata as well as the Mahabharata and different Puranas.
Chaitanya-chandrodaya-kaumudi (Bengali)
By Premadas (Purushottam Mishra). A verse adaptation to Kavi Karnapura's Caitanya-candrodaya-natakam drama.
Gaura-ganoddesha-dipika (c. 1576)
By Kavi Karnapura (Paramanand Sen).
Chaitanya-samhita (Bengali)
By Bhagirath Bandhu. Work follows the tradition of agama or tantric texts in its presentation as a story told by Shiva to his spouse.
Chaitanya-vilasa (c. 1500s; Odia)
By Madhava Dasa. A short poetical work in ten sections dealing with the life of Chaitanya. The poet probably came into contact with the saint when the latter came to Puri.
Gauranga-vijay (c. 1500s)
By Chundamani dasa. Biographical epic, believed to have been written in three volumes, only part of the first volume still exists. It contains some information about Chaitanya, Nityananda and Madhavendra Puri not found elsewhere.
Sriman-mahaprabhor-asta-kaliya-lila-smarana-mangala-stotram (c. late 1600s; Sanskrit)
By Visvanatha Chakravarti. Eleven sutras (seed verses) describing the eternal eight-fold daily pastimes of the fair-complexioned Lord.
Sri Gauranga-Lilamrta (c. late 1600s – 1700s; Bengali)
By Krishna Dasa (disciple of Visvanatha Chakravarti). Expounded on his guru's eleven sutras, often quoting verses from Vrindavana Dasa Thakura's Chaitanya Bhagavata, plus songs by Narahari Ghanashyama (author of Bhakti-Ratnakara) and Lochana Dasa (author of Chaitanya-Mangala).
Caitanya-upanisad
A book that is a part of the Atharvaveda which offers overwhelming evidence of Lord Caitanya's identity as the Supreme Lord and Yuga Avatara.
Sri Caitanya-caranamrta Bhasva (1887)
By Srila Bhaktivinoda Thakura. Commentary on an original handwritten manuscript of the Caitanya-upanisad from one pandita, Madhusudana Maharaja, of Sambala-Pura.
Amrita-pravaha-bhashya (c. late 1800s – early 1900s; Sanskrit)
By Bhaktivinoda Thakur. Commentary on Caitanya-upanisad.
Anubhāsya (1915)
By Bhaktisiddhanta Sarasvati. Commentary on Krishnadasa Kaviraja's Caitanya-caritāmṛta
Śrī Caitanya-caritāmṛta (1974; English)
By A. C. Bhaktivedanta Swami in English with original Bengali and Sanskrit. Commentary on Krishnadasa Kaviraja's Caitanya-caritāmṛta, based on Bhaktivinoda Thakur's Amrita-pravaha-bhashya and Bhaktisiddhanta Sarasvati's Anubhāsya commentaries.
Krishna-Caitanya, His Life and His Teachings (2014; English; ISBN 978-91-981318-1-9)
By Walther Eidlitz, originally written in German - Kṛṣṇa-Caitanya: sein Leben und seine Lehre, and published by Stockholm University, 1968, as a part of the scientific series "Stockholm studies in comparative religion".
Identity
According to the hagiographies of 16th-century authors, he exhibited his Universal Form same as had Lord Krishna on number of occasions, notably to Advaita Ācārya and Nityānanda Prabhu.[30][31][32]

When Rupa Goswami first met the Chaitanya Mahaprabhu, he saw the divinity in him and composed the following verse:

"O most munificent incarnation! You are Krishna Himself appearing as Sri Krishna Caitanya Mahaprabhu. You have assumed the golden colour of Srimati Radharani, and You are widely distributing pure love of Krishna. We offer our respectful obeisances unto You."[33]

The evidence for the belief that the Chaitanya Mahaprabhu is an incarnation of Lord Krishna is found in the Srimad Bhagavatam:

In the Age of Kali, intelligent persons perform congregational chanting to worship the incarnation of Godhead who constantly sings the names of Kṛṣṇa. Although His complexion is not blackish, He is Kṛṣṇa Himself. He is accompanied by His associates, servants, weapons and confidential companions.

— Canto 11, Chapter 5, Verse 32[34]
In this way, my Lord, You appear in various incarnations as a human being, an animal, a great saint, a demigod, a fish or a tortoise, thus maintaining the entire creation in different planetary systems and killing the demoniac principles. According to the age, O my Lord, You protect the principles of religion. In the Age of Kali, however, You do not assert Yourself as the Supreme Personality of Godhead, and therefore You are known as Triyuga, or the Lord who appears in three yugas.

— Canto 7, Chapter 9, Verse 38[35]
Also in some other Scriptures like Vishnu Sahasranāma, Bhavishya Purana, Padma Purana, Garuda Purana there are references of Chaitanaya Mahaprabhu being incarnation of Krishna. Evidences such as the Krishna-varnam verse SB 11.5.32 have many interpretations by scholars, including Sridhara Svami who is accepted as authority by Mahaprabhu himself.[36]

Gaudiya Vaishnavas consider Chaitanya to be Lord Krishna himself but appearing in the covered form (channa avatar) who appeared in the Kali Yuga as his own devotee to show the easiest way to achieve Krishna Consciousness.[37] The Gaudiya Vaishnava acharya Bhaktivinoda Thakura had also found out the rare manuscript of Chaitanya Upanisad of the Atharvaveda section, which reveals the identity of Chaitanya.[38] There are various evidences in the Hindu scriptures to show that, Chaitanya Mahaprabhu was non-different from Krishna. Unlike the other avatars of Krishna he did not kill any demon. Mahaprabhu brought light to the chanting of Hare Krishna Mahamantra. According to Chaitanya Bhagavat, which gives a detailed description of Mahaprabhu's life, Mahaprabhu made a prediction that the holy name of Krishna will be sung in every town and village of the world and this is evident in the history. International Society of Krishna Consciousness was started by Srila Prabhupada in the USA, proved the prediction to be correct.[citation needed]