The reference being made in Revelation is Nero.

I have heard before how Nero may have been the one who caused the tribulations that early Christians went through - e.g. not being able to buy food without having his (Nero's) approval, but not necessarily in reference to Nero being the actual Antichrist himself.

So I looked it up, and according to https://en.m.wikipedia.org/wiki/Antichrist, that term is widely thought (e.g. Martin Luther, father of the Protestant reformation, and John Calvin) to not necessarily refer to Nero, or rather not just him alone. Similar to how a "man of the law" can refer to anyone who upholds it - a sheriff for example - a "man of lawlessness" can refer to anyone who opposes it.

Cool, TIL 😎