​It is difficult to talk about the historical demography of the Maghreb region before the eleventh century AH/ seventeenth century CE due to the dearth of records and statistics on population, soldiers, or tax collection prior to that time. However, the Islamic library possesses a particular kind of source –the biographical dictionary – which can shed light on topics related to micro-demography, such as births, deaths, average life spans, population distribution and movements, and the like. Based on data concerning 471 scholars (ulema) who lived in the Maghreb between the mid-eighth century and the late ninth century AH (mid-fourteenth to late fifteenth century CE), and taking into account the limited nature of biographical dictionaries with their focus on a particular social group, this paper attempts to assess the legitimacy of reliance on biographical dictionaries for historical demographical investigations by comparing the information provided by biographical dictionaries with statistical data available in other sources.