Srimad Bhagavatam - Summary and Study Guide - Eight Canto

SB 6.18.8: By His own potency, the Supreme Personality of Godhead, who has multifarious potencies, appeared in the form of a dwarf as Urukrama, the twelfth son of Aditi. In the womb of His wife, whose name was Kīrti, He begot one son, named Bṛhatśloka, who had many sons, headed by Saubhaga.

SB 6.18.9: Later [in the Eighth Canto of Śrīmad-Bhāgavatam] I shall describe how Urukrama, Lord Vāmanadeva, appeared as the son of the great sage Kaśyapa and how He covered the three worlds with three steps. I shall describe the uncommon activities He performed, His qualities, His power and how He took birth from the womb of Aditi.

The first seven Manus: 

Svāyambhuva Manu (1st): The first Manu, a son of Lord Brahma. His activities are introduced in SB 8.1.4. During his reign, the Lord appeared as the incarnation Yajña.

Svārociṣa Manu (2nd): The son of Agni. The Lord's incarnation during this period was Vibhu. SB 8.1.19.

Uttama Manu (3rd): The son of King Priyavrata. The Lord appeared as Satyasena during this manvantara. SB 8.1.23

Tāmasa Manu (4th): The brother of Uttama Manu. The Lord appeared as Hari (who notably saved Gajendra the elephant) during this era. SB 8.1.27

Raivata Manu (5th): Raivata Manu, the younger brother of Tāmasa Manu (the 4th Manu). The Supreme Lord appeared during this era as the incarnation Vaikuṇṭha. At the request of the Goddess of Fortune (Ramā), the Lord manifested a Vaikuṇṭha planet. According to the acharyas (like Vīrarāghava Ācārya), this specific Vaikuṇṭha planet is situated within this universe, above Lokaloka Mountain. This Vaikuṇṭha planet was only visible and accessible to the residents of this universe during the reign of Raivata Manu. Vīrarāghava Ācārya (the 14th-century Śrī Sampradāya commentator) specifically notes that because this planet is above the Lokaloka range, it stays visible to the highly elevated souls and demigods even after the Raivata Manvantara ends. SB 8.5.2 - SB 8.5.5 purport.

Cākṣuṣa Manu (6th): He follows Raivata and is described in SB 8.5.7. During his reign, the Lord appeared as Ajita, who famously advised the demigods to churn the Ocean of Milk.

Vaivasvata Manu (7th): He is the current Manu of our era. SB 8.13.1.

Chronological Timeline

Nila Varaha: Appears to kill Hiranyaksha (the first great demon of this cycle) and rescue the Earth from the cosmic ocean. (Referenced in SB 8.19.6)

Ajita (The Unconquerable): The specific form of Vishnu who appeared as the son of Vairaja and Deva-bhuti. He advised the Devas to make a truce with the demons and supervised the churning of the milk ocean. (SB 8.5.9-10)

Kurma: Acts as the pivot for Mount Mandara. While the Devas and Asuras churned the ocean, he sat at the bottom to provide a stable base for the mountain. (SB 8.7.8)

Dhanvantari: Emerges from the ocean of milk carrying the amrta-kalasha (the pot with the nectar of immortality). He is the father of Ayurveda. (SB 8.8.31-35)

Mohini-Murti: Appeared to enchant the demons and trick them to give the nectar to the Devas. (SB 8.9.1)

Matsya: Appears at the very close of the 6th Manvantara during the partial deluge (pralaya) to save King Satyavrata (who becomes the 7th Manu) and the Vedic knowledge from the flood. (SB 8.24.10)