Westphalia Treaty This treaty is regarded as the beginning of modern and secular state formation in diplomatic history. Westphalia Treaty can be considered as the first international conference of the European states which ended Thirty Years War between Habsburgs and Bourbons in 1648. With this treaty, division of Holy Roman Empire into more than three hundred principalities was recognized and the position of France in the European continent strengthened. After Westphalia Treaty, formation of independent states in Europe accelerated.