This thesis is a historical study of a corpus of Muslim carved tombstones known as batu Aceh (Malay for ‘Aceh stones’). The batu Aceh tradition emerged in the mid-15th century at the Sultanate of Pasai in coastal northern Sumatra and was rapidly adopted by numerous other Muslim polities in Sumatra and the Malay Peninsula. In subsequent centuries, batu Aceh were found as far north as central Thailand and as far east as North Maluku. This tradition, which lasted until the 19th century, is one of the most abundant types of extant Islamic material culture and many of them are amongst the earliest datable artefacts in maritime Southeast Asia. Existing scholarship, much of which is grounded in epigraphy, has yet to consider this vernacular tradition as a whole or address broader historiographical concerns.

Through an extensive dataset of batu Aceh from coastal northern Sumatra and the Malay Peninsula, as well as select case studies from South Sulawesi and Bima, this thesis offers a longue durée analysis of the development of the tradition and reveals patterns of continuity and change. I adopt an interdisciplinary approach in reconstructing the history of batu Aceh and offering new perspectives in interpreting its meaning and function. I use a wide variety of written sources – from historical chronicles, letters, travel accounts, colonial documents, and ethnography – as well as comparative material from Southeast Asia and other parts of the Islamic world.

This thesis covers the period immediately before the emergence of the batu Aceh tradition, its early formative period at the Pasai Sultanate, followed by its efflorescence in the 16th and 17th centuries at the Sultanate of Aceh. In the penultimate chapter, I discuss the adoption of the tradition at the Sultanates of Makassar and Bima, its continuation in Aceh in the time of the decline of the Aceh Sultanate, before delving into the factors for its demise in the late 19th century. The post-colonial period saw the revival of batu Aceh within ethno-nationalist frameworks.

This study of the batu Aceh tradition reveals evidence of various dimensions of Islamisation: from the role of Sufi spirituality, the intersection between religious law and practice, to the impact of models of kingship. Furthermore, it underscores the changing cultural circulations over time: the batu Aceh tradition drew upon connections with the wider Islamic world in its formative period but over time exhibited a ‘turning inward’ during a period characterised in scholarship as the age of vernaculars. Batu Aceh was synonymous with the prestige of the Sultanate of Aceh in the western Malay Archipelago, but as the tradition spread further east, it became a symbol of Malay-Muslim courtly prestige.