The Masoretes were groups of Jewish scribe-scholars who worked from around the end of the 5th through 10th centuries AD, based primarily in the Jewish centers of the Levant and Mesopotamia. Each group compiled a system of pronunciation and grammatical guides in the form of diacritical notes (niqqud) on the external form of the text of the Hebrew Bible in an attempt to standardize its pronunciation, paragraph and verse divisions, and cantillation for the worldwide Jewish community.