Herbert Hoover: Against That Communist Roosevelt, Karl Marx, John Maynard Keynes, and ???

Herbert Hoover, October 1936:

I rejected the schemes of economic planning to regiment and coerce the farmer. That was born of a Roman despot 1400 years ago and grew into the A[gricultural ]A[djustment ]A[ct]. I refused national plans to put government into business in competition with its citizens. That was born of Karl Marx. I vetoed the idea of recovery through stupendous spending to prime the pump. That was born of a British Professor...

I have no idea who the "Roman despot" was. Diocletian perhaps? But 1500 years would put us in the reign of Justinian...