Step 1: Origin with Brahmā.
Ayurveda's knowledge is traditionally believed to have originated from Brahmā, the creator.
Step 2: Succession to Dhanvantari.
Brahmā passed this knowledge down through sages, eventually reaching Lord Dhanvantari, the divine physician and an incarnation of Viṣṇu.
Step 3: Suśruta's Surgical Systematization.
Dhanvantari's disciple, Suśruta, codified surgical knowledge in the Suśruta Saṁhitā.
Step 4: Vāgbhaṭṭa's Compilation.
Vāgbhaṭṭa later synthesized this knowledge into texts such as Aṣṭāṅgahṛdaya, incorporating prior teachings.
Step 5: Chronological Sequence.
The established order is: Brahmā (D) → Dhanvantari (C) → Suśruta (A) → Vāgbhaṭṭa (B).