The Eastern Syriac script, properly termed Madnhaya (meaning 'Eastern' in Syriac) or Swadaya ('conversational' or 'vernacular'), is the script tradition preserved by the Church of the East (Assyrian Church of the East) and the Chaldean Catholic Church. Developed in Iraq Sasanian Mesopotamia and the theological centers of Nisibis, Seleucia-Ctesiphon, Beth Abe, and Adiabene between the sixth and eighth centuries CE, Madnhaya retains a graphical structure that remains significantly closer to archaic monumental Estrangela than Western Serto.
Graphically, Madnhaya is distinguished by its open, vertical, and angular letterforms. Unlike Serto, which compressed letter shapes into rounded baseline loops, Madnhaya preserves the distinct uncial posture of individual letters: alaph retains its independent vertical legs and central crossbar; kap maintains its distinctive wide baseline box; and final forms for kap, mem, and nun retain bold vertical descenders. Additionally, Eastern scribal tradition introduced mandatory terminal ligatures for taw-alaph and taw-yodh at word endings, creating decorative flourishes unique to Eastern codices.
The defining feature of Madnhaya codicology is its fully developed vocalization system, which operates entirely through supralinear and sublinear dots and short dashes without recourse to Greek letterforms. This point-based vocalization system evolved directly from the early Estrangela homograph dot system, expanding into a precise seven-vowel system that captures the exact phonetic nuances of the Eastern reading tradition. The seven Eastern vocalization marks are: Ftaha, Zqapa, Rbasa Arriha, Rbasa Karya, Hbasa, Esasa Allisa, Esasa Rwiha
Madnhaya also serves as the official script for writing Modern Eastern Literary Neo-Aramaic (Swadaya), which was standardized in the Urmia region during the nineteenth century. In both classical ecclesiastical manuscripts and modern Neo-Aramaic publications, Madnhaya texts are almost universally copied with complete vocalization, qushaya and rukaka points, and diacritical marks, presenting an elaborate graphic matrix that ensures exact phonetic preservation.