In this study we trace back the life of Reformed minister, dean and bishop János Gachal until his traceless disappearance. We also present the organisational development of the Reformed Church in southern Hungary at the moment of the collapse of Austro-Hungarian Monarchy and the border modifications that took place during the Second World War. János Gachal spent most of his ministry in southern Hungary where he experienced the horrors of both world wars. One can discover his integrity in a world that changed abruptly around him. He became active in saving communists, Jews and Yugoslav partisans. He was a skilled organiser of the congregations. The era of his ministry is characterised by a vibrant atmosphere regarding both the life of the church and the cultural and economic life of the communities. During the Second World War he has fallen victim to the unstoppable ethnical cleansing. Even today, nobody exactly knows what exactly happened and where was he buried.