Irish minors strategy
From EU3 Wiki
Which Irish nation to start with?
Out of the four Irish minors, three of them are really viable. Munster and Leinster have the advantage that if England takes Connacht right away you can still expand to two provinces, while Ulster is the richest province. Connacht is the poorest, often DoWed by England and has the worst strategic position to boot! Assembling the kingdom of Ireland is still possible but made much more difficult by your poverty and by being forced to attack Munster, which is larger and stronger than you, across a river.
Finances
The Irish countires suffer from not having massive incomes so you will have to max out your treasury bar if you want to many any significant ammount of ducats. This unfortunately results in very high inflation later in the game and there is little if any way to reverse this. The National Bank idea only reduces inflation by -.10 and you'll have to have the treasury bar very low for it to really make a difference. You may feel compelled to take out loans. DO NOT TAKE OUT LOANS!!! Loans are a massive trap for smaller poorer nations. Often you won't be able to keep up with the intrest incurred from the loans and you'll fall into bankruptcy which will make inflation horrible. If you can make the interest you will rarely if ever be able to pay the loan off, you'll keep extending until the interest is high and you'll fall into bankruptcy anyway.
Uniting Ireland
The first thing to do is wait a year or so. In that time the other minors will disband their armies and at least one of them should be allied with the other two. Pick that one and declare war on it. Be sure to annex it last! You should then be able to conquer all of them in short order.
Alternately, if you have a good warrior-king, you can start off by declaring war on them right away. Most of the time this is foolish, but occasionally if you wait England will beat you to the punch by attacking Connacht. If they do, everything becomes much harder (and uniting Ireland isn't easy to begin with).
After you've conquered the other minors, you will need to acquire Meath. It is the richest Irish province and well worth having, but it unfortunately is in English hands from 1453 to 1789. You don't actually have to take the fight to England though; beat enough of the armies they land and eventually they will start offering it to you. You shouldn't need more than 3 or 4 thousand cavalry. Once you've won enough fights (which you will; the English rarely stop coming) you'll have good enough military tradition to hire a top-rated shock general. At this point the English stop posing a threat and you can just slaughter them until they beg you to take Meath and go away.
Alternately, if you're really scared of them, you can sit tight and hope Meath revolts to you. England will eventually declare on you given time, however. Be sure to take Meath right away if they do! If you do not take it they will land thousands of troops there and take every province but one from you.
One game way to forestall this is to offer the release of one of the other minors. This works best if offered right after the English declaration of war, but can still work even after they've won some victories. This gets you out of the war for the cost of only one province.
Expanding
Once you've got Ireland united and have cores on everything, you're essentially a smaller, poorer Portugal. You're both out of the way from everyone and in a good position to colonize. I suggest finding yourself a nice, rich Carribean island no one else seems to want (I like Cuba) and settling in. Once you're strong enough, it's also fun to steal Celtic provinces from their owners when distracted. Be careful though, as they mostly belong to England and France which can seriously stomp you if they're not otherwise engaged.
Another good stratgey is to take out other smaller single or two province countires. The best places are in the mediterranean (Noxos, The Knights, Corfu, Crete, Cyprus etc), Germany (Saxony, Bradenburg, Wuttenburg etc), and Italy (Savoy, Milan, Genoa etc). Italy is the best place for this type of fighting. The italians rarely if every ally with one another and always end up fighting each other. They usually don't have very large standing armies and can be quickly conquered by 1 or two armies. Be careful on who you choose. By the time you are able to attack them they may have allies so keep tabs on the nations you want. The two best to go after are Genoa & Milan. Both of these nations boast populations 20 or more times the entire Irish home islands combined. They have very high tax revenues and Genoas main province is a center of trade.
