encompassing the Biblical, Roman, Byzantine, Umayyad, Abbasid, Fatimid, Crusader, Ayyubid, Mamluk and Ottoman periods – form part of the identity of the modern-day Palestinian people, as they have come to understand it over the last century. Noting that Palestinian identity has never been an exclusive one, with "Arabism, religion, and local loyalties" playing an important role, Khalidi cautions against the efforts of some extreme advocates of Palestinian nationalism to "anachronistically" read back into history a nationalist consciousness that is in fact "relatively modern". Khalidi argues that the modern national identity of Palestinians has its roots in nationalist discourses that emerged among the peoples of the Ottoman empire in the late 19th century that sharpened following the demarcation of modern nation-state boundaries in the Middle East after World War I. Khalidi also states that although the challenge posed by Zionism played a role in shaping this identity, that "it is a serious mistake to suggest that Palestinian identity emerged mainly as a response to Zionism." Conversely, historian James L. Gelvin argues that Palestinian nationalism was a direct reaction to Zionism. In his book The Israel-Palestine Conflict: One Hundred Years of War he states that "Palestinian nationalism emerged during the interwar period in response to Zionist immigration and settlement." Gelvin argues that this fact does not make the Palestinian identity any less legitimate: "The fact that Palestinian nationalism developed later than Zionism and indeed in response to it does not in any way diminish the legitimacy of Palestinian nationalism or make it less valid than Zionism. All nationalisms arise in opposition to some 'other.' Why else would there be the need to specify who you are? And all nationalisms are defined by what they oppose." David Seddon writes that "[t]he creation of Palestinian identity in its contemporary sense was formed essentially during the 1960s, with the creation of the Palestine Liberation Organization." He adds, however, that "the existence of a population with a recognizably similar name ('the Philistines') in Biblical times suggests a degree of continuity over a long historical period (much as 'the Israelites' of the Bible suggest a long historical continuity in the same region)." Baruch Kimmerling and Joel S. Migdal consider the 1834 Peasants' revolt in Palestine as constituting the first formative event of the Palestinian people. From 1516 to 1917, Palestine was ruled by the Ottoman Empire save a decade from the 1830s to the 1840s when an