The group of manuscripts known as the Masoretic Text developed over an extended period of time, beginning in the second century AD (Ashby, Go Out and Meet God, 5). It received its final form in the 10th century AD under Aaron Ben Asher of the Tiberian Masoretes (Tov, Textual Criticism, 24.) It is currently best represented in the Leningrad Codex, which is the base text for the Biblia Hebraica Stuttgartensia (BHS) and the ongoing work of the Biblia Hebraica Quinta.
The largest organized collection of Hebrew Old Testament manuscripts in the world is housed in the Russian National Library ("Second Firkovitch Collection") in Saint Petersburg. Codex Leningradensis is the oldest complete manuscript of the Hebrew Bible in Hebrew. Manuscripts earlier than the 13th century are very rare.