Jean Kellens is one of the foremost experts on Old Iranian literature for the last quarter of a century. He has dedicated his career to the elucidation of the most difficult of ancient literature, the Avesta, the holy book of the oldIranian Zoroastrians. Between 1988 and 1991 he published together with Eric Pirart a scholarly edition and translation of the oldest texts in the Avesta, including the Gathas ascribed to Zarathustra, that laid the foundation for modern work on these texts. Since that time he has continued to refine our knowledge of both these texts and the younger Avestan texts.