Āryabhaṭa states in the Āryabhaṭīya (Gaṇitapāda, verse 1) that he was setting forth in his work the knowledge that had been honoured in Kusumapura. The following verse speciﬁes that at a time when the results computed through the then prevailing ﬁve astronomical schools (siddhāntas) (viz., Vāsiṣṭha, Paitāmaha, Pauliśa, Romaka and Saura gave conﬂicting results, Āryabhaṭa, as the head of an institution (kulapa), set forth his modiﬁed system of astronomical computation in Kusumapura:
siddhāta-pañcakavidhāu api dṛgviruddha-
sūryaḥ svayaṃ Kusumapury abhavad kalau tu
bhūgolavit kulapa Āryabhaṭabhidhānaḥ ॥
"When the methods of the ﬁve Siddhāntas began to yield results conﬂicting with the observed results as in the case of setting of the planets, eclipses etc., there appeared in the Kali age, at Kusumapura, God Sun himself in the form of Āryabhaṭa, the Kulapa ('head of an institution') well versed in astronomy."
In spite of the well-known identiﬁcation of Kusumapura with Pāṭaliputra (modern Patna), the capital of the ancient Magadha country (Bihar), suggestions have been hazarded that if the Aśmaka country could be identiﬁed as Kerala, Kusumapura can be identiﬁed with the township of Pūṅkunnam near Trichur and if Aśmaka could be the same as Tamilnadu, Kusumapura can be identiﬁed with Pūmpuhār on the east coast. The puerile nature and far-fetchedness of both these suggestions would be obvious when it is noted that they do not conform even to the literal meaning of Kusumapura, "ﬂower city", since the two suggested words mean only "ﬂower hill" and "ﬂower river-mouth". There is neither an astronomical tradition nor such an institution in these two places, to sustain the epithet of Kulapa given to Āryabhaṭa.
Indian tradition, Hindu and Buddhists, Purāṇic and historical, is loud and clear in identifying Kusumapura with Pāṭaliputra, the capital of Magadha. In fact, Āryabhaṭa’s follower Bhāskara I himself states in his commentary on the Āryabhaṭīya that Kusumapura is Pāṭaliputra. Thus, in his commentary on Āryabhaṭīya (Gaṇitapāda, verse 1), he explains "Kusumapure ’bhyarcitam jñānam. Kusumapuraṃ Pāṭaliputram." The Sanskrit lexicons offer also alternate forms for both the names, viz., Kusumapura in Hemacandra’s Abhidhānacintāmaṇi (133.976) and Puṣpapura in Keśava’s Kalpadrukośa (10.18), Pāṭaliputra in the Abhidhānacintāmani (133.976), Pāṭaliputraka in Puruṣottama’s Trikāṇḍaśeṣa and Pura in Hemacandra’s Anekārthasaṅgraha (36.450). (9)