When did the Israel Palestine conflict start ?
First things first, the term “conflict” is inadequate to describe the Palestinian question. It holds within it connotations of symmetry, of two conflicting and equal parties, rather than a case of an indigenous population resisting colonial dispossession and ethnocide. It obfuscates that this is not some local squabble between two already existing populations, but a case of foreign settlers seizing land to construct an exclusivist ethnocracy at the expense of the natives. Settler colonialism, by its very definition, is unequal.
Now going back to your question, many have the impression that Israeli Jews and Palestinian Arabs have been locked in strife since the dawn of time - often producing a sense that nothing can be done to end the conflict. However, the roots of the “conflict” are relatively recent, and can be traced to the late nineteenth century. That is when Zionism - a political movement among European Jews that aimed to confront the problem of European anti-Semitism by establishing a Jewish state - selected Palestine as the site for that state.
The first Zionist colony was established in 1882 in the coastal plain of Palestine, near what is today Tel Aviv. Palestinians quickly realized that the Zionist movement threatened their own aspirations for freedom and self-rule. Prior to the advent of Zionism, Christians, Muslims, and Jews had lived in Palestine in relative harmony.