"During the 1948 Palestine war in which the State of Israel was established, around 700,000[fn 1] Palestinian Arabs, or 85% of the total population of the territory Israel captured, were expelled or fled from their homes.["
en.wikipedia.org/wiki/Causes_of_the_1948_Palestinian_expulsion_and_flight
I know that wikipedia articles are derided by some, but the references in this article are to respected historians.
The rest of the article is more detailed. I won't type/copy/paste another post as long as the previous one, just quote a couple of footnotes.
27) Slater, Jerome (2020). Mythologies Without End: The US, Israel, and the Arab-Israeli Conflict, 1917-2020. Oxford University Press, Incorporated. ISBN 978-0-19-045908-6.
“There is no serious dispute among Israeli, Palestinian, or other historians about the central facts of the Nakba. All of the leading Israeli New Historians—particularly Morris, Shlaim, Pappé, and Flapan—extensively examined the issue and revealed the facts. Other accounts have reached the same conclusions. For example, see Ben-Ami, "A War to Start All Wars"; Rashid Khalidi, "The Palestinians and 1948"; Walid Khalidi, "Why Did the Palestinians Leave, Revisited"; Masalha, Expulsion of the Palestinians; Raz, Bride and the Dowry.
Reviewing the evidence marshaled by Morris and others, Tom Segev concluded that "most of the Arabs in the country, approximately 400,000, were chased out and expelled during the first stage of the war. In other words, before the Arab armies invaded the country" (Haaretz, July 18, 2010).
Other estimates have varied concerning the number of Palestinians who fled or were expelled before the May 1948 Arab state attack; Morris estimated the number to be 250,000–300,000 (The Birth of the Palestinian Refugee Problem Revisited, 262); Tessler puts it at 300,000 (A History of the Israeli-Palestinian Conflict, 279); Pappé's estimate is 380,000 (The Making of the Arab-Israeli Conflict, 96). In another recent review of the evidence, the Israeli historian Daniel Blatman estimates the number to be about 500,000 (Blatman, "Netanyahu, This Is What Ethnic Cleansing Really Looks Like").
Whatever the exact number, even Israeli "Old Historians" now admit that during the 1948 war, the Israeli armed forces drove out many of the Palestinians, though they emphasized the action as a military "necessity." For example, see Anita Shapira, Israel: A History, 167–68.
28) Abu-Laban, Yasmeen; Bakan, Abigail B. (July 2022). "Anti-Palestinian Racism and Racial Gaslighting". The Political Quarterly, Vol. 93, Issue 3, p. 511:
"Palestinians have long known what happened to them in 1948 and its very human costs. However, the work of the ‘new’ (or revisionist) Israeli historians from the late 1970s also challenged the official state narrative of a miraculous wartime victory through access to material in the Israeli archives.
This has established what Ilan Pappé has summarised as the ‘ethnic cleansing of Palestine’, a process involving massacres and expulsions at gunpoint. In light of the ever-growing historiography, serious scholarship has left little debate about what happened in 1948. [...] However, Nakba denial remains a political issue of the highest order.