Cataloging is now complete on HMML's digitized manuscript collections from Yemen. These images were provided to HMML by the Zaydi Manuscript Tradition project (ZMT) at the Institute for Advanced Study in Princeton. They include 735 manuscripts from fourteen different libraries across the northern highlands of Yemen, primarily private family and scholarly libraries, but also several mosque and institutional libraries. The dated manuscripts in these collections range from 1118 to 1984 CE, and they include texts from the full history of the Zaydī legal and theological tradition, along with Qurʼans, devotional texts, and works from other branches of Islam. Almost all of the manuscripts are in Arabic, with a small number in Persian.

As a result of its relative isolation and unique traditions, the Zaydī community has preserved important literature from early Islamic schools of thought such as the Muʻtazilīs, while maintaining a rich scholarly tradition of its own. Unlike most Shīʻī traditions, the Zaydīs recognized an unbroken chain of imams (religious and political leaders) well into the 20th century, and they have historically placed a strong emphasis on choosing imams with scholarly knowledge. Thus, many of the most important texts in these collections were written by imams, including an autograph manuscript in the hand of the imam al-Manṣūr billāh, dated 1214 CE. Other texts are the work of other scholars, including some that attest to controversies and conflicts within the Zaydī community. One of the most important of these controversies was sparked by the arrival of Wahhābī ideology from central Arabia in the 18th century, and Zaydī authors took strong positions on both sides of this debate. The Yemeni collections in HMML's Reading Room preserve these texts and make them available to scholars around the world, most of whom cannot access Yemen itself due to the ongoing war in that country. View now