Though Birdie's answer seems to give an accurate overview, I feel there is a need to add some details regarding Victorinus and Augustin as evidence to address the question deeply.
Luther's sola-fide or faith-alone doctrine is defined as monergism which means man's efforts are vain, as he is totally incapable to be righteous; and the idea that no one was ever justified by the Mosaic law. It is based on the interpretation of Paul's arguments against works of the law can imply not just the Mosaic-covenant works but any effort to please God. I found a reference of Augustine of Hippo (5th century AD) that suggest the Lutheran interpretation. Augustine interpreted "works of the law" arguments can apply to moral-works in general - On Nature and Grace
Chapter 2 [II.]— Faith in Christ Not Necessary to Salvation, If a Man
Without It Can Lead a Righteous Life
Therefore the nature of the human race, generated from the flesh of
the one transgressor, if it is self-sufficient for fulfilling the law
and for perfecting righteousness, ought to be sure of its reward, that
is, of everlasting life, even if in any nation or at any former time
faith in the blood of Christ was unknown to it. For God is not so
unjust as to defraud righteous persons of the reward of righteousness,
because there has not been announced to them the mystery of Christ's
divinity and humanity, which was manifested in the flesh. 1 Timothy
3:16 For how could they believe what they had not heard of; or how
could they hear without a preacher? Romans 10:14 For "faith comes by
hearing, and hearing by the word of Christ." But I say (adds he): Have
they not heard? "Yea, verily; their sound went out into all the earth,
and their words unto the ends of the world." Romans 10:17-18 Before,
however, all this had been accomplished, before the actual preaching
of the gospel reaches the ends of all the earth— because there are
some remote nations still (although it is said they are very few) to
whom the preached gospel has not found its way—what must human nature
do, or what has it done— for it had either not heard that all this was
to take place, or has not yet learned that it was accomplished— but
believe in God who made heaven and earth, by whom also it perceived by
nature that it had been itself created, and lead a right life, and
thus accomplish His will, uninstructed with any faith in the death and
resurrection of Christ? Well, if this could have been done, or can
still be done, then for my part I have to say what the apostle said in
regard to the law: "Then Christ died in vain." Galatians 2:21 For if
he said this about the law, which only the nation of the Jews
received, how much more justly may it be said of the law of nature,
which the whole human race has received, "If righteousness come by
nature, then Christ died in vain." If, however, Christ did not die
in vain, then human nature cannot by any means be justified and
redeemed from God's most righteous wrath— in a word, from punishment—
except by faith and the sacrament of the blood of Christ.
Did Marius Victorinus of 4th century taught sola-fide? NO
The view among some protestants that Victorinus was the early or first champion of sola-fide doctrine might have been caused by misunderstanding his phrase faith-alone in Galatians commentary. Victorinus did make clear distinction between moral good works and the specific Mosaic-covenant works. Here is a quote from page 292 of the book Marius Victorinus' Commentary on Galatians, by Stephen Andrew Cooper
For all who live based on works of the Law are under a curse (3: 10).
Forcefully, then, he has added that not only are those who live based
on works not blessed, but also that those who live based on the works
of the Law are under a curse. Now, as he said based on works of the
Law, let us understand that there are also works which belong to
Christianity, especially those works which the apostle frequently
commands (and also what has been commanded to him: let us be mindful
of the poor) and the additional precepts for living which are included
in this apostle’s writings. Each one of these works is commanded by
the apostle to be fulfilled by every Christian. The works of the Law,
then, are something else: religious observances, obviously, offerings
of a lamb (although the Passover has now been fulfilled through
Christ); and there are further works which they do as well, pertaining
to circumcision and foods to be observed or prepared.