The UN has sponsored a series of peace talks between the two communities since 1980, but only the recent talks have shown signs of progress.
Negotiations to create a united Cyprus have continually been hampered by key issues such as the right of return to the north by Greek Cypriots and the withdrawal of Turkish troops from the island.
Cyprus's impending entry to the European Union on 1 May prompted renewed efforts to find a solution. If either side rejects the referendum, in effect only the Greek side will join - leaving aside the already impoverished Turkish side.
In 2003, the Turkish Cypriot authorities eased restrictions allowing people from both sides to cross the "Green Line" for the first time in 30 years. Within three days, some 17,000 people made the crossing.
In February 2004 UN Secretary General Kofi Annan managed to get leaders
of both sides to agree that if they could not reach agreement, he would present his own plan to the people direct - which in the event was what happened.