Since the publication of Professor J. Takakusu's ‘Life of Vasubandhu by Paramārtha’ in the year 1904, several scholars have made attempts to determine the date and works of Vasubandhu. The problem is beset with several difficulties. Tradition gives three dates (A.N. 900, 1000, and 1100) based on different reckonings of the Nirvana era. Vasubandhu, himself a Sautrāntika, is the author of the celebrated Vaibhāsika work, viz., the Abhidharma-kox015B;a (and its Bhāṣya), and is at the same time credited with the authorship of several major works of the Vijñānavāda school. The problem is rendered more complex by the mention in Yaśoṁitra's Sphuṭārthā Abhidharma-
kośa-vyākhyā of an elder (Vṛdāhacārya) Vasubandhu, leading to a recent theory of two Vasubandhus advocated by Professor E. Frauwallner.