Gradual exemptions released different persons and classes from this tax.

One edict exempts painters.

In Syria, all under twelve or fourteen, or above sixty-five, were exempted; at a later period, all under twenty, and all unmarried females; still later, all under twenty-five, widows and nuns, soldiers, veterani and clerici--whole dioceses, that of Thrace and Illyricum.

Under Galerius and Licinius, the plebs urbana became exempt; though this, perhaps, was only an ordinance for the East.

By degrees, however, the exemption was extended to all the inhabitants of towns; and as it was strictly capitatio plebeia, from which all possessors were exempted it fell at length altogether on the coloni and agricultural slaves.