A more recent example is the General Crisis of the Seventeenth Century in Europe, a period of inclement weather, crop failure, economic hardship, extreme inter-group violence, and high mortality. It was due to the Little Ice Age, caused by a period called the Maunder Minimum when sunspots were exceedingly rare. Episodes of social instability track the cooling with a time lap of up to 15 years, and many developed into armed conflicts, such as the Thirty Years' War (1618–1648). It started as a war of succession to the Bohemian throne. Animosity between Protestants and Catholics in the Holy Roman Empire (in modern-day Germany) added fuel to the fire. Soon, it escalated to a huge conflict involving all major European powers that devastated much of Germany. By the war's end, some regions of the Holy Roman Empire saw their population drop by as much as 70%. But not all societies faced crises during this period. Tropical countries with high carrying capacities and trading economies did not suffer much, because changing climate did not induce an economic depression in these places. Moreover, by the mid-eighteenth century, as global temperatures started to rise, the ecological stress faced by Europeans also began to fade. Mortality rates dropped and the level of violence fell, paving the way for a period known as "Pax Britannica", which witnessed the emergence of a variety of innovations in technology (which enabled industrialization), medicine (which improved hygiene), and social welfare (such as the world's first welfare programs in Germany), making life even more comfortable.