Lane (1840) first noted the beneficial effect of blood transfusion in controlling haemophilic bleeding following ophthalmic surgery. The appreciation that haemophilia is due to a plasma defect, at first thought to be prothrombin, coincided with the discovery of blood groups. This led in due course to the discovery of citrate anti-coagulant and the ability to store blood. The beneficial effect of citrated plasma in haemophilia led to the exploitation of stored blood, fresh frozen plasma, and the subsequent development of cryoprecipitate and factor concentrates. All this would not have been possible, however, without the selfless contribution of blood donors and the development of an organized blood transfusion service. In the United Kingdom, P. L. Oliver pioneered the development of blood donor panels, the London Blood Transfusion Service and the British Red Cross Society Blood Transfusion Service leading directly to the National Blood Transfusion Service; recognized as the World's senior service. The development of haemophilia therapy owes much, therefore, to Oliver's energetic and pioneering work and it is entirely appropriate that the first Oliver Memorial Lecture be directed to the evolution and future of haemophilia therapy. It is indeed an honour to be invited to deliver this Oliver Memorial Lecture at the combined meeting of the British Blood Transfusion Society and the British Society for Haematology here in Wembley.