http://www.juancole.com/2014/04/pictures-refuting-there_was_no_palestine.html
When the League of Nations created the Palestinian state, it had a population of 700,000, of which about 76,000 were Jews. Almost all of the latter had immigrated in the previous 70 years. In 1850 only 4% of the population had been Jewish. In 1799, Napoleon Bonaparte found only 3,000 Jews. There had been hardly any Jews in Palestine since about 1100 AD.
So not only was there a Palestine, full of hundreds of thousands of people, over millennia, but there was a very long period of near-absence on the part of Jews. This absence was not because of a forcible expulsion. Rather, Jews in Palestine had converted to Christianity, and then many of those converted to Islam.