it always baffles me to find out that nobody knows that palestine and philistine are the same word. that's right, there is evidence of palestinians in ancient judea, but they were not arabs, they were the outsiders known as philistines.
the bible is hardly a scholarly source for history, but it does provide a little bit of information about the palestinians, namely that they were much taller than the hebrews and were acknowledged by all as being from beyond the sea. it's otherwise not clear who they were, based on that paltry source.
egyptian sources connect the philistines/palestinians with a group of invaders during an event called the bronze age collapse, which egypt survived but which left most of the civilized world in ruins. a group of invaders, called the sea peoples, sailed in from the north and attacked egypt; egypt defeated these sea peoples and settled them in the levant. this is the origin of the philistines in the middle east, of which we take the name palestine, via the romans.
we know today that these sea peoples were a confederation of indo-european speaking peoples that included halstatt celts and dorian greeks and would have behaved almost identically to later viking raiders. this was about 3500 years before present, before rome and even mostly before greece, as we know it.
it follows that the philistines were actually a group of very early viking raiders and that they almost certainly spoke a dialect of greek. this is the origin of the ethnic term palestinian, but it does not accurately describe the origin of modern palestinians.
the romans changed the name of the province and some people surely left but the evidence strongly suggests genetic continuity, which means that the jews actually converted to (monophysite) christianity after the destruction of the temple before slowly converting to islam in a process that is called arabization. today, they call themselves arabs and muslims; the truth is that they are twice colonized jews.
when you understand that, it makes the whole conflict into a surreal joke. this is not an ethnic conflict at all, it's really strictly sectarian.