War of Spanish Succession and Utrecht System

The War of Spanish Succession was the result of a struggle between major powers in Europe to install the next monarch in Spain after the death of Charles II, who was childless. The wholesale acquisition of the Spanish Empire by a single nation would greatly upset the balance of power in Europe. Before his passing, Charles II appointed his successor to be Phillip V, the grandson of Louis XIV. This, however, opposed a prior arrangement made between England, the Dutch Republic, and France to install Charles VI, the second son of the Holy Roman Emperor Leopold I, and gift Spain's Italian territories to Austria and France. It is interesting to note that these deals were already being made while Charles II was alive, indicating that the other European nations were already worrying about the potential fallout of a new royal monarch in Spain far before Charles II' death. This proposed treaty would have effectively partitioned Spain and maintained the balance of power by dividing its territories among other nations. After Charles II' death, Phillip, the first Bourbon king of Spain, claimed the throne and immediately and sent troops to the Spanish Netherlands. This invasion caused other European powers to form an anti-France coalition in reaction to a potential unification between Spain and France. 

After 13 years, the Treaty of Utrecht was signed after a preliminary peace agreement, signaling the end of the conflict that stretched across Europe, even reaching North America. The treaty of peace was signed between France, Britain, the Dutch Republic, Prussia, Portugal, and Savoy. Chiefly, this treaty prevented the unification of the Spanish and French crowns, ensuring that the balance of power in Europe would be maintained and that France would not dominate the European mainland. Phillip was forced to renounce the right for him and any of his descendants to lay claim to France. The partitioning of Spanish territories outside of the Iberian peninsula was also implemented as Spain ceded its Italian possessions and the Spanish Netherlands to Austria. Spain and France also made concessions in the New World, losing territories and trading routes to Britain. As an already weakened power from years of war, Spain could not really afford these losses, and its status as a Great Power would be questioned moving forward. Note that the Holy Roman Empire was not involved in this treaty, and a state of war would continue to exist between France, Spain, and the Holy Roman Empire until a separate treaty years later.

This newly enforced balance of power system is the direct predecessor to what will be established at the Congress of Vienna. Throughout the early 18th century, this system was at the heart of European diplomacy as rival nations banded together against any opponent that was threatening the precarious balance of power.