Great Britain is number nine and Ireland is Number 20.
Unless you don't count Greenland, then GB is 8th and Ireland is 19th. (There is some dispute over Greenland really being 3 smaller islands under all that ice. Don't let it bother you; Ireland will always be 19th in my mind.
This post is not about islands, but if I had started out with corks and rebellion, you wouldn't have read this far down.
First, there is a difference between nationalism and republicanism. Nationalism is simply identifying with one's land and culture and being proud of it. Patriotism, even. On the other hand, republicanism is the desire to be an independent country, a "republic," technically, but independence is at the core.
One can be a happy nationalist and still be a part of a larger union. One would think.
The Act of Union of 1801 (I am writing this by memory, so please point out any inaccuracies) created the United Kingdom of Great Britain and Ireland. This is not something I learned in any American school, more's the pity. I had to learn it from you from before on this blog, or from researching posts for this blog - the origins of my meager knowledge are murky at best.
Be that as it may (you probably weren't taught that much about the Missouri Compromise or the Kansas-Nebraska Act, either) there was a union created between Great Britain and Ireland in 1801. Of that we may be sure, just as sure as Marley was dead at the beginning of A Christmas Carol.
Some say (some Irish say) that union was not completely and willingly two-sided, that they ("they" being the Irish) were sold out by bribe-taking turncoat politicians. Well, you know how it goes. Always the sour grapes from a minority. No one can say Ireland didn't benefit greatly, in many ways, over the years.
I need to go back to researching now to find out why Great Britain wanted a union with Ireland. The last time I did that, I got sidetracked by Henry VIII. That won't happen this time.
Probably there is more to come on the subject of Ireland. Didn't get very far this time.