The 17th century was an exceptional time in the history of Europe: the religious controversies generated a century before led to continuous conflicts, culminating in the Thirty Years` War. It was the century of international leagues as well, with a number of combinations on both sides according to religious or political considerations. This peculiar situation brought far-away parts of Europe together. No wonder the Protestant countries, England and Transylvania, found a common ground of interest: the defence of the Protestant faith and the maintenance of balance under the given circumstances. This work intends to trace down the contacts that existed between England and Transylvania in the first half of the 17th century, most particularly during the Thirty Years` War. There is a special emphasis on Anglo-Turkish connections in the 16th and early 17th centuries, and the role of the English ambassadors in Constantinople. Most of this work is concerned with the diplomatic-political relations between England and Transylvania, from the early stages to the end of the Thirty Years' War. I would like to say a special thank you to Miklós Lojkó for his assistance and guidance.