The oppression and persecution of Jews, in the Eshkenazis' homeland of Bulgaria and throughout Eurasia, has taken place since at least the Roman Empire. Anti-Semitism, both on a religious basis and, later on, a racial basis, has ranged from expulsion to enslavement to the large-scale genocide of which we are all too familiar. It's historically omnipresence is such that it cannot be adequately described in a few pages. The following details will therefore arbitrarily begin with the twentieth-century migration of Jews, which included Bulgarians, to what would become the contested state of Israel.
The story of Jewish peoples' return to Israel in the twentieth century is rooted in the widespread and millennia-long yearning to return to the land where their religion was established. The disputed rights to these lands are fundamental to the history of Abrahamic religions. Jews, Muslims, and Christians have participated in a perpetual cycle of conflict over the area that Jews refer to as "Zion" or the "Land of Israel". The specific conditions of World War One and its Arab revolt meant that, just as the British made a commitment to help Jews with their return, the peoples who lived there (including some Jews from prior migrations) were in a particularly violent and turbulent state. When British-assisted Jewish migrations in the 1920s and 1930s increased the area's Jewish population exponentially, Jews experienced immediate resistance from Palestinians.
When Israel declared its independence in 1948, Arabs from throughout the region invaded the area in defense of their peers in Palestine. During this nearly yearlong war, many from both sides died or lost loved ones. When Israel overwhelmed the Arab army, hundreds of thousands of Palestinians fled their homes and suffered as they traveled to find safety. When the 1967 Six-Day War took place between Israeli and neighboring nations who supported Palestinians, Israel is considered to have struck first.