The UN agency for Palestinian refugees has unveiled a trove of pictures and film captured over more than 60 years chronicling the collective memory of those who fled or were forced into exile. Established in 1949 to help Palestinian refugees who lost their homes when the state of Israel was created a year earlier, UNRWA has digitised the archive and put it on display in east Jerusalem. More than half a million negatives, prints, slides, films and videocassettes collected by the United Nations Relief and Works Agency show men, women and children eking out new lives in refugee camps across the Middle East. Called "The Long Journey," a collection of the works has been on display at the Al-Ma'mal Centre in east Jerusalem since Thursday. "This project is important for the history of Palestine and Palestinians, in order to defend and preserve their identity," UNRWA commissioner general Filipo Grandi said at the launch of the exhibit. "It is a contribution for building a national heritage" and "a beautiful project to help the Palestinian diaspora to preserve their identity." Former UNRWA filmmaker and photographer George Nehmeh contributed over the years countless pictures and videos of refugees and landscape, some of which no longer exists. Nehmeh, a Lebanese, prepared a special documentary for the exhibit, in which he says "each frame is a snapshot of history that is indelibly part of the Middle East." At the onset of the 1970s Nehmeh took pictures of refugees in the Gaza Strip's Khan Yunis camp and the Baqaa camp just outside Amman. Forty years later he went back in search of some of them. A skeletal, dehydrated year-old baby he once photographed clutching his mother is now a father of five, and the documentary shows Nehmeh reunited with him in Gaza. Another snapshots shows a couple who have fled Jericho after the 1967 Six Day War to the misery of a refugee camp. Now they proudly boast 70 to 80 grandchildren and great grandchildren. UNRWA is estimated to care for about five million Palestinian refugees in impoverished camps in the West Bank, Gaza Strip, Lebanon, Jordan and now war-hit Syria. Because of its historical and cultural significance, the archive has been inscribed UNESCO'S "Memory of the World" list since 2009. Grandi said UNRWA chose to digitise its Palestinian archive because it was "literally decaying" and the task is being undertaken by young students in Amman and in Gaza. Denmark and France have provided technical assistance, and Palestinians have privately provided funds for the mammoth project. The question of Palestinian refugees is among the main stumbling blocs between Israel and the Palestinians, including the status of Jerusalem, the borders and Jewish settlement constructions. Palestinians insist the refugee issue be resolved on the basis of UN Resolution 194, which defines principles for their "right of return." During a visit to the West Bank headquarters of the Palestinian leadership earlier this month, French President Francois Hollande called for a "realistic solution" to the refugees problem. At the opening of the exhibit, PLO executive board member Hanan Ashrawi said: "The issue of the refugees is crucial. It is such an essential embodiment of all Palestinian issues. "The refugees must have the right to choose (to return) and the recognition by Israel of its guilt and of our narrative and their rights". But Israeli Prime Minister Benjamin Netanyahu has repeatedly said the Jewish state is opposed to the return of the refugees and their descendents.