Life expectancy in Western countries has increased enormously during the past two centuries. This rise was accompanied by a change in the cause-of-death pattern in which so-called degenerative diseases (cardiovascular diseases, cancers) gradually replaced infectious diseases (cholera, TB, etc.). The timing of this epidemiologic transition is well-known for Belgium and many other countries, but it is still unclear how this transition varied by social groups and residence. We don't know how the transition occurred and who benefited first and most. Which groups were and remained the most vulnerable, and for which causes of death was that the case? Using the unique cause-of-death register for the city of Antwerp collected via a large crowdsourcing project (www.sosantwerpen.be), we examine social inequalities and spatial variations in cause-specific mortality during the nineteenth and early twentieth centuries. Based on a mixed-method approach and GIStorical Antwerp, we investigate how cause-specific mortality varied within the city of Antwerp according to age, sex, occupation, origin and residence, and which factors can explain this. As the largest Belgian city at the time with high population turnover and vast socioeconomic changes, Antwerp is a unique laboratory to examine how mortality inequalities arise and develop. Port cities in the past acted as ‘gateways of disease’. The current corona crisis reflects the urgency of an in-depth study on inequalities at death in the past.