Sophronius of Jerusalem also negotiated a pact with Caliph Umar, known as the Umariyya Covenant or Covenant of Omar, allowing for religious freedom for Christians in exchange for jizya, a tax to be paid to conquered non-Muslims, called "dhimmis".[24] While the majority population of Jerusalem during the time of Arab conquest was Christian,[25] the majority of Palestine population about 300,000-400,000 inhabitants, was still Jewish.[26] In the aftermath the process of cultural Arabization and Islamization took place, combining immigration to Palestine with the adoption of Arabic language and conversion of the part of local population to Islam.[27]