In pictures: The Long Journey chronicles decades of Palestinian struggle

Despite the upheaval, schooling continued and there are now more than 700 UNRWA schools, providing an education for about half-a-million children. Courtesy UNRWA

With problems of overcrowding, outbreaks of disease were a major concern in the early days of the Palestinian refugee camps. Courtesy UNRWA

Early Palestinian refugees were created in two main waves - from the Middle East war of 1948, and in 1967 when Israel occupied the West Bank, Gaza Strip and East Jerusalem. Courtesy UNRWA

A visitor looks at photographs displayed during an exhibition organised by UNRWA at the Al-Mamal Centre in the Old City of Jerusalem. 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. AFP

There are 58 recognised refugee camps in Jordan, Lebanon, Syria, the West Bank and the Gaza Strip. They are administered by UNRWA, which was formed in 1949. Courtesy UNRWA

Palestinians make up one of the biggest displaced populations in the world. Some five million are registered as refugees with the UN. Courtesy UNRWA