Leon Gerlis was one of the unsung heroes of paediatric cardiology. A proper pathologist, he nurtured his interest in the morphology of the congenitally malformed heart through three careers. Qualifying in the middle of the Second World War from University College Hospital in London, he spent his first career in Grimsby, Lincolnshire, where he learnt the rudiments of all aspects of pathology, being appointed consultant at Grimsby General Hospital in 1963. While training in Grimsby, he was fortunate in two regards. First, and most importantly, he met and married Daphne, who then supported him unstintingly throughout the remainder of his careers. Second, his period of training in Grimsby coincided with the tail end of the career of James Brown, one of the initial pioneers of paediatric cardiology, and another unsung hero.Reference Wilkinson, Gerlis and Anderson ¹ Encouraged by Brown, Leon started collecting the hearts from infants and children who had died from congenital cardiac disease. Not only did he collect and analyse the hearts, he mounted them for ongoing display and research, and produced the most detailed documentation of the anatomical and clinical details of each case. This resulted in the production of an atlas of photographs that could be viewed in three-dimensional manner by using a specially designed set of spectacles. This work, appearing in 1954, was years ahead of its time, and like much of Leon's early work was soon forgotten. It remains, nonetheless, one of the landmarks in our understanding of the structure of the congenitally malformed heart. The advice given by Brown to Leon during their initial collaborations is also worth remembering. Leon became a little impatient at the time spent by Brown in checking the proofs of their atlas. Brown commented “Gerlis, I have my reputation to maintain, you still have yours to make. We must always check our work most carefully”.Reference Wilkinson, Gerlis and Anderson ¹ Leon followed the advice to the letter throughout his subsequent researches, as he established his own significant reputation.

I was fortunate to meet Leon for the first time in the mid-1970s. I had just published one of my early studies on cardiac development. Leon wrote to congratulate me on its appearance, and invited Anton Becker, with whom I was working in Amsterdam, and myself to visit him in Grimsby. We were overwhelmed not only by his hospitality, but by the treasure-trove that he had already created in his delightful home, and by the added jewels that remained within the hospital department. He subsequently collaborated with us in producing several of our initial descriptions of congenital cardiac diseases.

When the time came for Leon to retire from his practice in general pathology in Grimsby, the opportunity arose for him to become more deeply involved with his major interest, and he became the pathologist to the heart unit then established at Killingbeck Hospital in Leeds. This in turn led to his collaborations with Stanley Goldberg, in Tucson, Arizona, as well as with his paediatric cardiology colleagues working in Leeds. He collated, and analysed in detail, the archive then existing in Leeds, producing several more fundamental studies. After several years of working in Leeds, Leon decided that the time had come for another “retirement”, and moved to London. His thirst for knowledge, nonetheless, was unfulfilled, so he accepted the invitation to work at Royal Brompton Hospital, becoming Visiting Professor at Imperial College.

His energies at Brompton were amazing. Not only did he study intently the existing archive, but he also integrated the collection already put together at the National Heart Hospital by Jane Somerville into the Brompton archive, and added the very best specimens from his own initial collection, and the archive he had now established in Leeds. The result was the Leon Gerlis Museum, still maintained at Royal Brompton, and now properly recognised as one of the main resources for teaching and research into congenital cardiac disease in the United Kingdom. In his final years at Royal Brompton, he took the responsibility for teaching the multiple fellows coming to London to learn about the findings in adults with congenital cardiac disease. He also continued to study and describe the findings in the overall spectrum of heart lesions as seen in the paediatric age range, taking great interest in malformations of the outflow tracts. In this area, he continued to make inferences from his life-long interest in cardiac anatomy as seen in reptiles and fishes, this interest itself having been fostered by his connections with the once-thriving fishing industry of Grimsby.

It should not be thought, however, that his interests were confined to cardiac anatomy. He led a full and fascinating life, and was rightfully respected for his commitment to his religious community, and to his other interests, such as the St John Ambulance Brigade. As was stated in his hesped, there was no need to exaggerate his multiple contributions in all aspects of life. His contributions to paediatric cardiology remain in his multiple publications, but more importantly in the archives that he established and preserved. His overall career also serves as the model for those of us who believe that, while we still have things to contribute, we should be permitted to continue. He will be sorely missed. Those of us who were fortunate to know him well will take solace from his considerable legacy.