EBTs, such as the four principal Nikayas/Agamas, were not collected and compiled in the Buddha’s chronology of practice, or with events & teachings happening in more chronological order.
The four basic texts were collected and then compiled at the first and second councils according to the 9 angas (classifications).
E.g. in various suttas there is a mention of: "the discourses, mixed prose and verse, expositions, verses, inspired utterances, quotations, birth stories, marvelous accounts, and questions-and-answers. ":
“And how is a bhikkhu one who knows the Dhamma? Here, a bhikkhu knows the Dhamma: the discourses, mixed prose and verse, expositions, verses, inspired utterances, quotations, birth stories, marvelous accounts, and questions-and-answers." (AN7.68 Bhikkhu Bodhi’s translation).
According to Ven. YinShun,
“the discourses, mixed prose and verse, expositions”, i.e. angas 1. Sutra/Sutta, 2. Geye/Geyya, 3. Vyakarana/Veyyakarana are found in SN/SA (i.e. the synthesis of the first three angas). (See also: Choong Mun-keat, “Ācāriya Buddhaghosa and Master Yinshun 印順 on the Three-aṅga Structure of Early Buddhist Texts”, Research on the Saṃyukta-āgama (Dharma Drum Institute of Liberal Arts, Research Series 8; edited by Dhammadinnā), Taiwan: Dharma Drum Corporation, August 2020, pp. 883-932.)
“quotations, birth stories, marvelous accounts, and questions-and-answers”, i.e. angas 6. Ityuktaka, 7. Jataka, 8. Vaipulya, 9. Adbhuta-dharma were compiled in MN/MA, DN/DA, AN/EA.
“verses”, i.e. anga 4. Gatha corresponds to certain texts of Sutta-nipata; “inspired utterances”, i.e. anga 5. Udana is Dhammapada. Both compiled in the Khuddaka-nikaya rather than being made part of the four basic Nikayas/Agamas.
See pp. 9-11, notes 32, 34, 36 (in Choong Mun-keat, The Fundamental Teachings of Early Buddhism):
Pages 7-11 from The Fundamental Teachings of Early Buddhism Choong Mun-keat 2000.pdf (434.6 KB)
Cf. also: