You could argue that there is some history in the Bible, but a lot of it is not history at all.

I mean, you can functionally argue this with any book. Certainly, there are a great many people who take Biblical events as historical facts. And that's precisely because of the success of centuries of militant evangelism. Which takes us back to the whole "history written by the victors" thing. If nothing else, the Council of Nicaea - hosted by Constantine the I - was an explicitly recognized congregation of "winners". And they were very literally codifying the historical narrative of what would become the largest religion on earth for at least the next millennium.

Also, the Old Testament was written by the Jews while they were part of the Persian Empire

The Old Testament that we refer to in the modern Bible is but one version of the original manuscripts maintained by Jewish priests living in a minor kingdom at the far edge of the Persian Empire. It persisted in large part because Judaism gave way to Christianity, which became the state religion of the continent spanning Roman Empire. Had Constantine lost the civil war with Maxentus, there's no saying what the prevailing religion of the Mediterranean (and then the rest of the world) would have been. But I suspect we'd have seen at least a few notable variances to the modern incarnation of the faith.