From an outside tip I have been thinking again about the massive conflict known as the 'Eighty Years War'. Basically this decided the fate of the modern Low Countries, Dutch independence from Spain and the boundaries between Protestant and Catholic religions in the area. This was very much an international conflict or perhaps to say, in more modern terms, a proxy war on the part of the major Catholic and Protestant powers. The Dutch easily had the most allies and help. The German states that were mostly Protestant (Lutheran) sent their formidable troops to help and most importantly the English, recently Protestants again, sent major help with their powerful navy and tens of thousands of soldiers. The Spanish had almost no outside help. The French were fighting each other and even the Catholic Bourbons of France had usually seen as rivals the Catholic Hapsburgs who ruled Spain and Austria. The Austrians were naturally with Spain but they had the Turks to worry about and their own problems with Germany. The Dutch were also very good fighters, inventing many new tactics especially in siege warfare. They also had alot of money from their merchant capitalism and control of vital trade ports.
The Spanish had some advantages, the infantry Spanish tercios pikemen were world renowned and they had a very talented commander in the person of Alexander Farnese, Duke of Parma (raised in Spain but born, married and later headquartered in Brussels) but he died in 1592. Although he had brought the Dutch almost to defeat, intervention by the English navy saved the Dutch Protestant cause from disaster. The English at this time were a dominant power. At the height of Queen Elizabeth I the English had a presence in Europe, aiding French Protestants and the Dutch, their navy asserted control of northern waters, they ruled Ireland and since bringing about the downfall of Mary Queen of Scots also dominated Scotland. The English were safe at home after beating the "Invincible" Armada and could resume their strategy of wearing down Spain by supporting rebelling Protestant forces in Europe. However, in 1594 traditional leaders of the native Catholic population in Ireland started a rebellion against English rule. This was to have an important indirect impact on the war in the United Provinces/Spanish Netherlands (Netherlands and Belgium and Luxembourg).
Ireland was often a problem for England but never too serious and this was at first not taken too seriously. However, when the Irish rebels won a major victory over the English at the battle of Yellow Ford the government in England realized they were facing a possible disaster. With just a little outside help (from Catholic powers like Spain) it seemed possible that the Irish might even be able to drive out the English and restore their independence. This fear caused the Queen of England to recall the majority of English forces from the Netherlands and send a great big army to Ireland under the Earl of Essex. However, he was not a good commander and after the Irish humiliated he was later put to death by the Queen. On the other hand, when Spain sent a small army to help the Irish (using the English strategy against them) they ended in failure also. This took the wind from the sails of the fighting powers in the Netherlands and soon a truce was arranged and though fighting resumed after that both sides had consolidated their positions and the Protestant-Catholic boundaries settled into their mostly continuous status.
This was ultimately very significant for Belgium, even the modern country of today. The Irish were finally defeated, their traditional leaders driven into exile and England started the policy of moving settlers to Northern Ireland to maintain their control. So, the rebellion did not work out very well for the Irish. However, their rebellion may have saved the life of Belgium. Keep in mind that one of the few things that have always been something in common of the Belgian people has been the Catholic Church. It might have been destroyed all those centuries ago. If the Irish had not went to rebellion the English could have kept their army in the Netherlands to fight the Spanish there and help the Dutch (who were doing pretty good already). Because of the Irish the English had to shift their attention and finally had many more troops in Ireland than in the Low Countries. If they had not had to do this it is probably very likely that the Dutch and allied Protestant forces could have totally defeated the Catholics, taken over the Spanish Netherlands and suppressed the Catholic Church from the whole region. Because of this, it can be seen that, indirectly, the Irish rebellion, even though it failed for them, their sacrifice allowed the Spanish Netherlands, later Catholic Belgium, to survive.