The second phase of construction at the Ajanta Caves site began in the 5th century. For a long time it was thought that the later caves were made over an extended period from the 4th to the 7th centuries CE, but in recent decades a series of studies by the leading expert on the caves, Walter M. Spink, have argued that most of the work took place over the very brief period from 460 to 480 CE, during the reign of Hindu Emperor Harishena of the Vākāṭaka dynasty. This view has been criticised by some scholars, but is now broadly accepted by most authors of general books on Indian art, for example, Huntington and Harle.