Palestinian president Mahmoud Abbas and Hamas leader Khaled Meshaal have ended a four-year feud at a reconciliation ceremony in Cairo.
The men lead the two Palestinian administrations in the West Bank and Gaza that have been locked in a bitter rivalry since 2007.
Abbas said the Palestinians had decided to “turn the black page of division forever” in signing the new unity pact.
Meshaal said that their sole struggle is against Israel and said the days of infighting are “behind us.”
Many ordinary Palestinians have long been calling on the two sides to settle their differences.
Islamist Hamas expelled the secular Fatah movement from Gaza and seized control of the territory in June 2007, over a year after it had won the Palestinian parliamentary elections.
Abbas said on Tuesday that Hamas would not have to amend its charter and recognise Israel under the deal.