The Old Swiss Confederacy a "de facto" independent state throughout the early modern period, although still nominally part of the Holy Roman Empire until 1648 when the Treaty of Westphalia ended the Thirty Years' War. The Swiss Reformation divided the confederates into Reformed and Catholic parties, resulting in internal conflict from the 16th to the 18th centuries; as a result, the federal diet () was often paralysed by hostility between the factions. The Swiss Confederacy fell to invasion by the French Revolutionary Army in 1798, after which it became the short-lived Helvetic Republic. The adjective "old" was introduced after the Napoleonic era with ,
Siege of Breda (1624) thereafter. The siege of 1624 captured the attention of European princes and, along with other battles like White Mountain (1620), played a part in the Spanish army regaining the formidable reputation it had held throughout the previous century. In the latter stages of the combined Eighty and Thirty Years' wars that had greatly strained Spanish resources, Breda was lost to the Dutch under Frederick Henry after a four-month siege. In the 1648 Treaty of Westphalia that ended the Thirty and Eighty Years' wars, it was ceded to the Dutch Republic. There were several motives for Spinola's siege of Breda. Because