Haj Amin al-Husseini
Mattar's 1988 book, "The Mufti of Jerusalem: Al-Hajj Amin Al-Husayni and the Palestinian National Movement", was "the first full-length biography" of Haj Amin al-Husseini. He was the editor of the "Encyclopedia of the Palestinians", published by Facts on File in 2005. Mattar has also published in "Foreign Policy", "Middle East Journal" and "Middle Eastern Studies" and was one of the experts featured on National Public Radio's seven-part series, "The Mideast: A Century of Conflict", in 2002.