You may be familiar with current events in Northern Ireland. This history goes back to a time when Scots from Southern Scotland and Northern England colonized Ulster which is Northern Ireland.
But why did the Ulster-Scots migrate from the Scottish Marches to Northern Ireland?
There is an oft-repeated scenario in Medievel Europe involving something called a March. Please click through to the Wikipedia Article to see the long list of Marches all over Europe!
To summarize, a March is a border region or frontier region where the Presiding Lord, often titled a Marquise was allowed additional fortifications and military capability above and beyond that allowed ordinary Nobility.
And so this oft-repeated scenario was that in a border region or March, the local Nobility would have the means to enrich themselves with repeated cross-border raids. But this unfortunately always came at the expense of the local population, thus the motivation to flee to Ulster.
King William III
So let's circle back.
King James II (and VII)
So what was King James' problem?
King James II was thown out of office because he was Catholic, because his second wife Mary of Modena was also Catholic, and because together they parented James Francis Edward and raised him as a Catholic.
Ok, let's circle back to the Williamite War in 1689.
It turns out that while King James II was deposed as King of England, Ireland, and Scotland, he still had an armed force in Ireland with which he fought a war against, and was defeated by, King William III in Northern Ireland. This is when the Ulster-Scots became known as supporters of King Billy.
But why was William of Orange installed as King? I am not going to answer this question.
But it should be noted that William of Orange was also the ruler of Holland, Zeeland, Utrecht, Guelders, and the Dutch Republic. And the context for this is that throughout the 17th Century, England and the Netherlands had been fighting a series of disastrous and expensive wars against each other known collectively as the Anglo-Dutch Wars.
Indeed it was just prior to the Second Anglo-Dutch War that New Amsterdam became New York.
The purpose of the Anglo-Dutch Wars was to establish control of International Colonial Trade, but it was believed that having a single King and Ruler of both England and several countries in the Lowlands would create peace.
Principality of Orange
As an interesting aside, let's just point out that the Principality of Orange came into existence in 1163 per Holy Roman Emperor Frederick Barbarossa in order to serve as a March in the context of his conflict with the Papacy.
While I have not read the book, the Television Series Born Fighting from the Smithsonian Channel is also narrated by Senator James Webb and is very fun and interesting to watch.