Northern Ireland is not part of England or part of the map of England :-/ :-/ :-/ it is not "ruled" by England, England has no claim to it, other than to uphold the democratic wishes of the people who live there.It has exactly the same status as Scotland and Wales - one of the four constituent countries of the United Kingdom.
The land itself doesnt belong to Ireland for two reasons
1. There is no such country as Ireland, ther are two countries on the Island of Ireland - Northern Ireland and The Republic of Ireland.
2. In Democratic Western Europe a land doesnt belong to one country or another , it belongs to (for [political purposes at least) the people who inhabit it, and the majority of the people who inhabit the country of Northern Ireland very much wish to remain an integral part of the U.K.

Northern Ireland is in no way a commodity, quite the reverse actually, in monetary terms it has cost British taxpayers huge amounts of money and if Westminster politicians could have found some way off getting rid of it quietly, they would have done so by the early/mid 70,s.
"English" soldiers - presumably speaking of the British army(English/Welsh/Scottish/N.Irish) didnt invade Northern Ireland btw. Their presence was actually reqeusted by the Catholic/Republican community.
Back to the Bloody Sunday issue - it was beyond belief that the enquiry took over 12 years and cost something like £180million to come to its conclusions. Apparently at least 17 lawyers have become millionares out of it.
I do hope that the families concerned can now have closure on the matter and it has now been put to bed so to speak, and the media and lawyers will have no more mileage out of it.