Thirty Years War: Catholic vs Protestant Massive war: Peace of Westphalia Treaty in 1648. Portuguese Trading Posts and Maritime activities in the Indian Ocean: 16th Century. Thirty Years War of religious intolerance: Indecisive result which led to sovereignty of countries for religious preferences. During today's session on the Thirty Years War and the Portuguese Trading in the Indian Ocean, Kaitlin was well focused and interactive with these important topics.