The Westphalian peace treaties of 1648, agreed after years of negotiation, drew to an end the devastating Thirty Years War, which had raged across Europe, with the greatest effect on the German lands, from 1618-1648. What had begun as a battle between religious ideals had escalated to include sizeable territorial claims.
The question of the consequences of the peace is important, as after all, we need to understand what the thirty years of fighting served to change (if anything) and what the important outcomes of the conflict were. The legacy of Westphalia remains something firmly entrenched in the consciousness of the 21st century; one will often hear the concept of the ‘Westphalian System’.
Arguably, the three most significant consequences of the peace proved to be: 1) an important shift in the balance of power within Europe, 2) religious tolerance, and 3) the establishment of the concept of state sovereignty.
The balance of power shifts
The emergence of France as a major power is a significant outcome of the peace conference. Surpassing Spain, the Habsburgs, and the ailing Holy Roman Empire, France was on an upward trajectory, with new territory in the bag, including Alsace-Lorraine. The Swiss and Dutch gained their independence, and there were important gains for an upcoming power, Brandenburg.
Following the peace settlement, an agreement of religious tolerance in individual lands was signed, with state sovereigns afforded the right to choose the religion of their subjects. At Westphalia, the outcome of the earlier Peace of Augsburg was recognised, and therefore the signatories accepted the concept of Cuius regio, eius religio (whose realm, his religion). Crucially therefore, Calvinism joined the list of acceptable faiths alongside Catholicism and Lutheranism.
The establishment of the concept of state sovereignty
As noted, one often hears the concept of the Westphalian System of separate, sovereign states. In truth, it was not long before nations were running roughshod over this concept. If anything, the difference was that nations began to recognise that in future conflicts and invasions, they were running roughshod over something in a less abstract manner than before.
In any case, the concept of sovereignty was real and lasting, even if any hope that it would prevent nations from trampling over it did not last for long. It was akin to a teenager sticking a DO NOT ENTER sign on his door, which meant that when his unruly younger sibling came charging in, he could angrily point at the sign before telling his parents about the intransigence.
The Peace of Westphalia was, in many ways, a strange conference. It took months to agree on the basics of how the conference would even work, and when it did begin, Catholics and Protestants were kept apart, and there was even disagreements within national representatives. The French ambassadors were not even on speaking terms with each other.
The Thirty Years War essentially began with the act of pushing an unlucky individual through a window, and in following this theme, ended with something of a protracted squabble in the lounge.
V. Liulevicius, War, Peace, and Power: Diplomatic History of Europe, 1500-2000, (The Great Courses: Audible, 2008)
M.E. Wiesner, Early Modern Europe, 1450-1789, (Cambridge: Cambridge University Press, 2006)
The text of the agreement, http://avalon.law.yale.edu/17th_century/westphal.asp