This article employs, for the first time, the private archive of one of the world's largest and oldest reinsurance companies, Swiss Re, founded in Zürich in 1863, in order to analyse the early development and internal workings of reinsurance – the insurer's insurance – in nineteenth-century Europe. In the course of overcoming existential crises during its early years, the company's management learned valuable lessons about the technical basis of reinsurance and the importance of information and communication. In the long run, this experience enabled Swiss Re to gain a greater autonomy of action for professional reinsurers within the insurance industry as a whole.