Its a tale that all little children learn. The making of the union jack. Once upon a time, there were two countries in a place far far away. They were called Scotsville and England. England was filled with a lot of crazy people with crazy ideas, who thought up great things like Toofball (but thats a story for another day..). The people from Scotsville thought those English are kinda cool. And so England and Scotsville made a union. They decided to be buddies, simply put. But they had a bit of a problem, they had two separate flags. So now which to choose to be the new flag was the question that puzzled these great minds of old. They thought and thought and after much pondering they decided to combine them (the hardest of problems usually has the simplest of solutions >.>). This was the first version of the Union jack.
Then to cut this long tale short, N. Ireland thought they might as well join in the party. But they also said they had their own flag, de ja vu? Well it was decided to stick the St. Patrick’s cross into the union jack, thus creating our current version. That’s how we got the union jack. But the home nations still use their old flags on occasion. Now in this story you might notice, Scotsville and N. Ireland got a fair deal and were included in the flag making, but Wales wasn’t! Well that question can easily be answered, nobody likes the welsh.

And with that i conclude our tale.
And actually rabb, the other countries are not under a tyranny. This might surprise you but they are "free".

If they want to split from the United kingdom, all they simply have to do is make it law in their parliament. Recently Scotland thought about it, but in the end decided to stay.
@lil-chan - the flag there <<<<<

@pirate - Dude, where ya been. I've been bored out of my skull. Leaving a comrade to the depths of boredom is low...i would never have thought it of you.