Marcelo Nuno Duarte Rebelo de Sousa was born on 12 December 1948.
He is Catholic and has been a member of several Church movements.
He has a Degree in Law from the Faculty of Law of the University of Lisbon, with a final mark of 19/20.
He completed a PhD in Legal and Political Sciences in 1985, with Distinction and Commendation awarded by unanimous decision.
He became a tenured Professor in 1992, appointed by unanimous decision.
After beginning his teaching career in the area of Legal and Political Sciences, he was in charge of the main disciplines of the Legal and Political Science Group.
He has chaired the scientific and pedagogical boards and the Institute of Legal and Political Sciences of the Faculty of Law of the University of Lisbon.
He has been an ex officio member of several bodies, such as the University Senate, and a member of the panel of judges for the University of Lisbon Award.
Representing the Faculty of Law of the University of Lisbon, he was head of the delegation which concluded the first agreement with the Faculty of Law of Bissau, and he has lectured at Agostinho Neto and Eduardo Mondlane Universities and the University of Eastern Asia.
He has been a Professor at the Faculty of Social and Human Sciences and the Faculty of Law of the Portuguese Catholic University.
He has been a member of the steering committee and the scientific board of the Faculty of Law of the University of Oporto, which has awarded him an Honoris Causa Doctorate.
He has been Secretary of State for the Presidency of the Council of Ministers, Minister of Parliamentary Affairs, and a member of the Council of State (2000-2001 and 2006-2016).
He has been President of the Municipal Assembly of Cascais, local councillor and leader of the opposition in the Town Hall of Lisbon and President of the Municipal Assembly of Celorico de Basto.
He was one of the founders of the People’s Democratic Party, later the Social Democratic Party, and was party leader from 1996 to 1999.
He has been Vice-President of the European People’s Party, of which the Social Democratic Party is a member.
He was involved in founding the Expresso and Semanário newspapers, where he held management roles.
He has been a regular political commentator since the 1960s, first in the press and later on radio and television.
He was a member of the committee that drew up the first Press Law.
He has chaired or been a member of the managing bodies of several associations, social solidarity institutions and the Santa Casa da Misericórdia of São Bento de Arnóia.
He has been a member of the Managing Council and Chairman of the Board of the Casa de Bragança Foundation and curator at the National Museum of Ancient Art and the Vieira da Silva-Arpad Szenes and António Quadros Foundations.
He is a patron of the Celorico de Basto public library.
He received the Commendation of the Order of Saint James of the Sword from former President of the Republic Mário Soares and the Grand Cross of the Order of Henry the Navigator from former President of the Republic Jorge Sampaio.