I answered a similar question about a week ago that may be interesting.

The relevant part:

" Palestine has been under the control of foreign powers for millennia and so Palestinians have historically been a melding of these disparate influences. There has long been a "Palestinian people" of sorts, but the definition of who they really were was hard to answer. That is to say, it was rather straightforward throughout most of the region's history to determine if you were a Palestinian citizen: were you born there? Did you live there? If so, you were. But what that really meant or implied was much harder to answer. More recently (post-Israeli), even the first parts are in question. According to Rashid Khalidi in his book Palestinian Identity: The Construction of Modern National Consciousness:

... in Palestine many powerful and contradictory views of self and of history are conjoined. These may be religious, whether Jewish, Christian, or Muslim: or secular, as for example the focus on Masonic ritual on the Temple in Jerusalem; or they may be national or supranational, whether Arab or Jewish.

Later:

... [S]everal overlapping senses of identity have been operating in the way Palestinians have come to define themselves as a people, senses that have not necessarily been contradictory for Palestinians themselves, but can be misunderstood or misinterpreted by others. As Palesinian identity has evolved over time, its elements have varied, with some eventually disappearing and others newly emerging.

The first inklings of a true Palestinian identity started to come about in the late 19th to 20th centuries with the spread of nationalism. The disparate peoples of the Ottoman Empire began, before and after the partitioning, to explore concepts of ethnic identity on a local level, how they interrelated, and how they related to the Ottomans. After the partitioning, without the Ottoman Empire's cultural buoying effects, the different regions of the former empire were free to explore and establish their unique identities in an independent context. Palestine, because of its unique situation during and after the Mandate period, has lagged behind somewhat. Unable to define a nationality in regards to a geographic area like other countries (other than a relatively nebulous idea of "homeland"), they've historically had trouble identifying those unique Palestinian characteristics.

This may skirt the 20 year rule, but even to this day, there's tremendous debate amongst scholars about who the Palestinians actually are, and whether or not they're exclusively Arab, Muslim, or even have to be from Palestine/Israel."

That is to say, the Palestinians are not an "invented" people, and their identity is not dependent on their antagonism to modern Zionism. That was a relatively common accusation in the past (seemed particularly common about a decade ago, I think?), and has been largely discredited with increased scholarship. At the same time, their identity has not been as stable throughout history as say, Bedouins, Egyptians, or Turks. Some people seem to make the claim that the overlap and fluidity of the importance of different aspects (the status of emigrants, Palestinian Christians, etc) denies them the status of a unique, historical people, which in my personal opinion is overly pedantic, if not outright hypocritical.

To say that Palestinians are an invented people is a rather moot point, as most people living in a modern day nation state has invented a national identity at some point and thus they would be invented peoples (for a lack of a better word). You could for example say that "Americans are a invented people, who did not exist before 1776". Of course there were people who lived in the 13 colonies before 1776, but the USA did not exist until 1776, and thus the American people, to mean a people living in the USA was invented in 1776. You could say the same for every nation state today, as most countries either invented a national identity after the creation of their nation (German and Americans), or invented it over time (French or British). So, to say the Palestinians are a invented people would not be wrong per se, just irrelevant, as they have a national identity today. If they viewed themselves as Ottoman subjects, Arabs or something else before they started viewing themselves as a Palestinian people is just a irrelevant as what the Americans viewed themselves as before they became Americans.

The claim was initially made by Zionists and Israelis, seeking to say that Palestinians were nothing but Arabs trying to differentiate themselves to stop Zionism. But that's not necessarily the case, and I explain why in heavy detail here.

The thing is, the claim continues to get credence as a result of a few different statements by Palestinian leaders. For example, reference is often made to the PLO Charter of 1968, which says:

Palestine is the homeland of the Arab Palestinian people; it is an indivisible part of the Arab homeland, and the Palestinian people are an integral part of the Arab nation.

In addition, there are other statements non-academics point to. For example, Zahir Muhse’in, a member of the PLO Executive Committee, reportedly said:

The Palestinian people does not exist. The creation of a Palestinian state is only a means for continuing our struggle against the state of Israel for our Arab unity. In reality today there is no difference between Jordanians, Palestinians, Syrians and Lebanese. Only for political and tactical reasons do we speak today about the existence of a Palestinian people, since Arab national interests demand that we posit the existence of a distinct “Palestinian people” to oppose Zionism.

These statements ignore what Palestinian nationalism really is: self-identification. What makes me American or Israeli or Palestinian? I decide that. A nation is nothing more than a group of people with share collective memory, culture, ideals, etc.. They don't have to be unanimous, but people collectively self-identify one way, and that's what Palestinians are. They came later to the party than most, but not as late as one might think. Palestinians, like Pakistanis, have a sense of national pride. But how old is the idea of Pakistan? Not very.

So you get the idea. I explained in response to another person that all nationality would arguably be "invented", the question is when and how the nationality gets invented. You can read my reply:

Are not all people "invented"? All nationalist ideals and categories are, indeed, invented. The question of when they were "invented" is an interesting one, but the idea that they are not "invented" is as false as saying that "Zionism" was not invented. At some point, someone decided to categorize themselves in a way different from another. Palestinian identity was "invented" and crystallized not just as a response to Zionism, but as a general outgrowth resulting from the collapse of the Ottoman Empire, the failure of pan-Arab ideology or Islamist ideology to fill that gap, and the need to create a rallying cry to unite the people behind common ideologies and shared ideals.

As much as I loathe his politics, I agreed with Dani Dayan when he observed that the Palestinians and the Israelis have equally compelling, yet mutually irreconcialiable claims on the land. The Palestinians enjoy a recent ethnic connection to it, whilst for the Jews it's an inseparable but distant part of their cultural identity. Therefore, it would be incredibly magnanimous for the dominant military power (currently Israel but could have easily been the Arabs had the 1948 war swung the other way) to accommodate the national aspirations of the other side.

It's not a particularly inspired world view but I think it's grounded in reality and (unfortunately) in status quo thinking.

This is a touchy issue that is calling for downvote brigades from both sides rather than sane historical debate.

Whenever I touch the subject, I refer to the excellent United Nations documentation: HISTORY OF THE QUESTION OF PALESTINE.

It is very detailed, yet still very readable, in spite of the enormous pressure that its authors must have suffered.