Albeit the motives have not yet been firmly established, Ottoman subjects who were on the Habsburg hereditary domains in 1823, 1824, and 1825 were registered by Habsburg officials. However, only the time frame in which the registrations were made is implied by these three years. A person's past fifteen or even thirteen years of information could occasionally be found out in the registers. Name, age, religion, and/or nationality were listed, as well as information about family members if they were travelling together, the location of the registration, a description of physical characteristics and information about clothing details or fashions, the date and place of birth, information about the person's occupation, and all relevant passport details, such as the reason for the passport's issue as well as the date, location, and authority responsible for it. Additionally, the registrar's own opinions or statements towards the individual or group whose information he was tasked with registering may be found in the registers. Intentions to remain in the destination were also questioned of those present. These registers—conducted in German, Italian, and occasionally Latin—have been preserved in three large books (Bücher in German) at the Austrian State Archives in Vienna. Over the course of more than one and a half years, they were decoded into an Excel sheet for a PhD project. Employing the information acquired, this study seeks to shed light on some socioeconomic and demographic trends about these Ottoman subjects who travelled to, from, and/or via Habsburg-ruled areas. This attempt would contribute in filling a noticeable gap in historiography that has so far resulted in the disappearance of eighteenth and nineteenth century Muslims in relevant literature composed of a large amount of work on non-Muslim communities, particularly Orthodox merchants. The ultimate goal, however, is to inspire more research into the topic by providing a more comprehensive picture of the socioeconomic and political developments that took place in the late eighteenth and early nineteenth centuries and that brought people from various societies together, with a focus on all Ottoman subjects, regardless of their ethnicity or religious affiliations.