Which scholar was the earliest to suggest that the Harappan state was ruled by autocratic priest-kings?

The regimented cantonment of Harappa may suggest the priest-controlled industries of Sumer. It may even be permissible to propose a priest-king for Mohenjodaro. On the other hand, in such sculptural art as the Indus has produced there is no real affinity with the sculpture of Sumer. No one would mistake a stone carving from Mohenjodaro for one from Tell Asmar or Mari. The Indus terracottas are in a different world from those of Mesopotamia. The art of the Harappan seals has no close parallel in the whole history of glyptic. The particularities are literal, local interchange, while the common generalities are the product of stray seeds readily fertilized in similar historical and geographical settings.