From the My Palestine site:
Among the over 11,650 Palestinian prisoners locked up inside Israeli jails, there are 325 “veteran prisoners”. The “Veteran Prisoners” is an expression used by prisoner movements and organizations to refer to Palestinian prisoners who have been locked up in Israelis jails since before the signing of the so-called peace agreement between Israel and the PLO in 1993. There are 108 Palestinian prisoners who have spent more than 20 years inside Israeli jails. These prisoners are called the “deans” of Palestinian prisoners. According to Abdel Nasser Farawna, a Prisoner Affairs expert, 20 of those belonging to “deans of prisoners” list are from Jerusalem, 16 are from the Palestinian Territories occupied in 1948 and 72 are from the Occupied West Bank and the Gaza Strip. Among the Palestinian “deans of prisoners” there are 13 prisoners who are in Israeli prisons since more than 25 years.These prisoners are:
Na’il Saleh Al Bargouhti, 52 years old, Ramallah, in prison since 04.04.1978 (31 years, 6 months) and is thus the longest-standing political prisoner in the world.
Fakhri (Asfour) Abdallah Al Bargouthi, 55 years old, Ramallah, in prison since 23.06.1978 (31 years, 4 months)
Akram Abdel Aziz Mansour, 47 years old, Qalqilya, in prison since 02.08.1979 (30 years, 2 months)
Fouad Qasem Al-Razem, 51 years old, Jerusalem, in prison since 30.01.1981 (28 years, 8 months)
Ibrahim Fadel Jaber, 55 years old, Hebron, in prison since 08.01.1982 (27 years, 9 months)
Hasan Ali Salma, 51 years old, Ramallah, in prison since 08.08.1982 (27 years, 2 months)
Othman Ali Misleh, 57 years old, Nablus, in prison since 15.10.1982 (27 years)
Sami Khaled Younis, 77 years old, from ‘Ara, in prison since 05.01.1983 (26 years, 9 months)
Karim Yousif Younis, 51 years old, from ‘Ara, in prison since 06.01.1983 (26 years, 9 months)
Maher Abdel Latif Younis, 52 years old, from ‘Ara, in prison since 20.01.1983 (26 years, 9 months)
Salim Ali Al Kayal, 56 years old, from Gaza, in prison since 30.05.1983 (26 years, 4 months)
Hafith Qundus, 46 years old, from Yafa, in prison since 15.05.1984 (25 years, 5 months)
Issa Abed Rabbo, 46 years old, from Dheisheh RC, in prison since 20.10.1984 (~ 25 years)