Thank you Robbie and blackbird! I was the attacker, if you mean who declared war on whom. If you mean in any of the specific battle, it was mixed. I think in general, I am still such a newbie, and also still coming from my previous experience in EU2 where battles remained largely at the strategic level. Yes, even there, the basics of who had the most troops, was there a leader, and morale+tech+discipline mattered. Here, though, EU4 has seemed to really make steps towards being more of a tactical battle game. Not fully...I'm still able to just roll armies around strategically and not worry generally, but I can tell there's much, much more that one can do relative to army make-up, the battleground and so forth. I'm a very old military gamer, so I'm familiar with all the general particulars, but I think the thing that bothered me the most (in this war and in the one with the OE a few decades before) is how the enemy armies just randomly appeared. Of course, it wasn't really random, but an example of how the computer can deal with multiple things at once and I cannot. LOL. I've realized that I must put the speed on slow, and when I'm watching an enemy stack, pause often to see exactly when it will arrive or when it has changed direction so I can then plan any attempted countermove.
As to your point, blackbird, about composition, the main army that was causing the most problem was like half infantry and half cannons, while my armies were more 60-20-20, maybe a bit more cannons. And, like I think I said, the Spanish general had 2 stars while mine only had 1.
To your question about economy, as you all have taught me, by focusing on trade, my economy is very strong. I did lose some money during the war, but had enough in the bank that it was never an issue. I did buy mercenary armies for the quick build, as you noted, and it allowed me to stabilize the war. And this time I did a much better job of watching my manpower. I've been working on this, completing Quantity idea as well as building some of the key army buildings. It got a bit low in this war, but I was watching it carefully to help guide me as to when to peace out, and take what I could get rather than getting greedy.
But, I am learning as I hope I convey with what happened next, so on with the story. Things went quickly over the next few decades. It has been fun. I did go ahead and release Naples as a vassal and picked up Sicily as a vassal after this first war with Spain (1566-1571). Two years later, the Commonwealth invited me into their war that involved the OE. I took my Spanish lessons to heart and made sure I kept my armies together and on a tight leash. I lost one battle, but was able to recover well enough to ultimately take Constantinople. It obviously helped that the main OE armies were up in the Commonwealth. Those are the two largest army nations, so they were really slugging it out, but I was able to really turn the tide for the PLC. I wasn't sure what kind of peace deal I would get, so in the end I peaced-out to take Zora and Cattaro, surrounding Venice and Ragusa. To try and weaken the OE more, and protect my flank, I made them release Herzgovina (I've allied them and trying to vassal, but part of the Empire, so....) and Montenegro. OE war was 1573-1577
While resting, I considered going for Tunisia after PLC made the OE drop them from alliance, but Portugal swooped in to protect them. ???? grrr, but I decided that since France still didn't like me and Spain now hated me, that I didn't need to anger the one other nearby nation that I might want to ally with to help with Spain. So, in 1579, I took out Venice and the Knights. In the peace deal, I took the Knights separately, and then released them as a vassal. Then with Venice, I took Spalato and Crete, but gave Crete to the Knights. Since you guys have all taught me about feeding my vassal, I realized that I can use the Knights in later wars with the OE to control the Aegean.
Now meanwhile, the diplomatic story changed in that France went to war with Spain and crushed them (1576-1581/82). This was what you had foreseen blackbird!
As you can see with the map, France took northern Iberia. So, now, instead of trying to befriend France, I see that they are going to remain a threat that I will need to deal with. But, since Spain was clearly beat up, I did war #2 with Spain (Nov 1581-Dec 1584). This time it was a Reconquest war as you guys had suggested (had to hunt to figure it out, but finally saw it). This one was much easier and was able to take both Madrid and Toledo during the war. I was able to take more of southern Italy for Naples (Molise, Avellino, Salerno, and then tried the "return core" thing in the peace deal to learn that such means the enemy gives land back to the other nation....I made them give the core back on Capitanata). And I gave Siracusa and Messina to give to Sicily.
Last bit of the story....right at the end of my war, about a month after, the PLC and Austria solved my alliance issue when they went to war with each other over some small German state. As you can see, the PLC is gigantic now (and I think a war with Muscovy is certainly coming). I decided that since I needed Austrian and Cillian land, and because I realized that Savoy was never going to accept a vassal stance (I even tried a quick save strategy to give Savoy back their two core provinces which, while it made it a little better, they still have that "member of the Empire" thing that kept the score against me)....I went with the OE and helped them destroy Austria. I almost conquered all of Savoy by myself, in which I was going to take all the land and then release them back to as a vassal (maybe...too many allies penalty has me pondering), but I couldn't take down the Level 3 Fort on Ciamberi.
During all this time, I finally realized the "province of interest" tool actually helps guide the AI as far as peace deals come. In that first war with the OE, I peaced out ahead of the PLC because I wanted those specific provinces. But by the time of Austria, I decided to try using the province of interest and in the peace deal that the PLC got with Austria, they gave me all the land that I wanted on the Adriatic: Trieste, Rijeka and Licca. That war was from Feb 1585-June 1587.
Whew. So, its a brand new game. The Commonwealth is my only real ally currently. Naples, Sicily and the Knights are my vassals. I do have Herzegovina as an ally, but they won't be much. Was thinking I could vassal-feed them more of the Balkans, but at least for now, I can't beat the "member of the Empire" tag. I'm busily sending all of my missionaries around to convert all these places that were Protestant.
There will be a third war with Spain, even though strategically it would probably be better to hit France first. Not sure the best path to get to that. England can't seem to recover from Scotland, and for some reason they are allies with Spain alongside Scotland. And of course we'll go again with the OE a few more times. Based on what else you've all told me, I will need to deal with the Mamluks soon enough too, but every time I try to go into North Africa, there's a snag. LOL.