Why is Ireland southern Ireland and the Republic of Ireland
The term "Southern Ireland" is an informal term used for the Republic of Ireland, to distinguish
wiki.answers.com/Q/Why_is_Ireland_southern_Ireland_and_the_Republic_of_Ireland

Is southern Ireland called Southern Ireland or just Ireland
It's called Ireland. According to Article 4 of the Constitution, "the name of the State is Éire
wiki.answers.com/Q/Is_southern_Ireland_called_Southern_Ireland_or_just_Ireland

Who separated Ireland from northen Ireland
It's a VERY long story, so look it up, but basically, it was the British. They took Ireland's land.
wiki.answers.com/Q/Who_separated_Ireland_from_northen_Ireland

Why is Ireland named Ireland
for Ireland *Iveriú . It was also the name of a goddess
wiki.answers.com/Q/Why_is_Ireland_named_Ireland

Is Belfast in Ireland or Northen Ireland
Both. Belfast is on the island of Ireland, in the part of it that is known as Northern Ireland.
wiki.answers.com/Q/Is_Belfast_in_Ireland_or_Northen_Ireland

Ireland (city, IN)
Ireland, Indiana Ireland —   Town   — Ireland Coordinates: 38°24′53″N
www.answers.com/topic/ireland-in

IRELAND
www.answers.com/topic/ireland-4

Ireland (family name)
Ireland Frequency: (5609) (number of times this surname appears in a sample database of 88.7
www.answers.com/topic/ireland-5

Ireland (first name)
Ireland Gender:  Feminine Usage:  English Pronounced:  IER-land  
www.answers.com/topic/ireland-1

Ireland (flag)
Ireland Flag Description: Three equal vertical bands of green (hoist side), white, and orange
www.answers.com/topic/ireland-6