Erez is a graduate student who studies the Ashkenazic Piyyutim (liturgical poems) written in the 12th century, in response to persecution of Jewish communities which accompanied the 1st and 2nd Crusades, and several other more minor events. He has focused mainly on the works of Rabbi Kalonymus B. Yehuda, a survivor of the persecution of 1096 in Mainz, seeing them as a valuable source for the documentation of both the actual events as they unfolded in the Ashkenazic communities, and as a mirror for the literary and liturgical response of the Jewish population for them. He holds a B.A. in History and Education from the Hebrew University. His M.A. thesis, under the supervision of Professor Elisheva Baumgarten, is aimed to study additional poets associated with the school of Mainz, in the next generations. This in turn will hopefully provide a better understanding of the relationship between the poems, their authors, the community and liturgy at large.