Tertullian

“ They are constantly throwing out against us that we are preachers of two gods and three gods, while they take to themselves pre-eminently the credit of being worshippers of the One God; just as if the Unity itself with irrational deductions did not produce heresy, and the Trinity rationally considered constitute the truth. We, say they, maintain the Monarchy (or, sole government of God) . ”

“ Nay more, I contend that no dominion so belongs to one only, as his own, or is in such a sense singular, or is in such a sense a monarchy, as not also to be administered through other persons most closely connected with it, and whom it has itself provided as officials to itself. If, moreover, there be a son belonging to him whose monarchy it is, it does not forthwith become divided and cease to be a monarchy, if the son also be taken as a sharer in it ”

“ Now you must understand the overthrow of a monarchy to be this, when another dominion, which has a framework and a state peculiar to itself (and is therefore a rival) , is brought in over and above it: when, e.g., some other god is introduced in opposition to the Creator, as in the opinions of Marcion; or when many gods are introduced, according to your Valentinuses and your Prodicuses. Then it amounts to an overthrow of the Monarchy, since it involves the destruction of the Creator. [8] ”