The Army of Flanders formed the longest standing army in the early modern period, operating from 1567 until 1706. It was established following a wave of iconoclasm in the troubled provinces of the Netherlands in 1565 and 1566. The provinces were ruled by the Spanish King Phillip II, and as trouble mounted he decided to reinforce the existing forces of the governor, Margaret of Parma, with a more substantial force. This was both a political reaction against the perceived rebellion, but also a response to the Calvinist views being shown by the protesters, establishing a religious flavour to the military response.