This research project is addressing why people convert to Islam and how this can be manifest archaeologically. The contemporary relevance of these issues is immediately apparent in the context of globalisation and increasing interest in Islam. “Becoming Muslim” is transforming our knowledge about Islamisation processes and contexts through archaeological research in Harlaa and Harar, Eastern Ethiopia, a region never previously archaeologically investigated. Assessing genuine belief is difficult, but the particular impact of trade, as well as Saints, Sufis and Holy men, proselytisation, benefits gained from Arabic literacy and administration systems, enhanced power, prestige, warfare, and belonging to the larger Muslim community are all relevant. Equally significant is the context of conversion. Why were certain sub-Saharan African cities key points for conversion to Islam, e.g. Gao and Timbuktu in the Western Sahel, and Harlaa and then Harar in Ethiopia? The “Becoming Muslim” project is exploring these issues and examining and presenting them comparatively through publications, a major conference, and in museum displays.