recently, the fourth école normale supérieure was created in January 2014 under the name of École Normale Supérieure de Rennes (pure and applied sciences, economics and management, law school, sport) in Brittany. All four together form the informal ENS-group. The École normale supérieure is also an institution of PSL Research University, a union of several higher education institutions, all located in Paris, which aims at achieving cooperation and developing synergies between its member institutions to promote French research abroad. In addition to this, the École normale supérieure cooperates in Atomium Culture, the first permanent platform for European excellence that brings together some of Europe's leading universities, newspapers and businesses. The school is a member of the Conference of University Presidents and of the Conference of Grandes Écoles. Domestic partnerships Its educational project being based on research, ENS seeks to train its students to become researchers. The main objective of the education given is getting a doctorate, and more than 85% of normaliens achieve this. The students are free to choose their own course of study but must at least attain a master's degree in research. Since, traditionally, the institution does not have the powers to grand university degrees, students have to follow courses in other universities in Paris. To this end, ENS cultivates a large number of partnerships and conventions with other higher education institutions to create master's degrees which are co-presided by two institutions. ENS works closely with the École des Hautes Etudes en Sciences Sociales (EHESS), the Paris-Sorbonne University, the Panthéon-Sorbonne University, HEC Paris and ESSEC Business School in particular to deliver joint diplomas to a certain number of students who have followed courses shared between the two institutions. It is also the main partner in the Paris School of Economics project which it has launched along with the EHESS, the École Nationale de la Statistique et de l'Administration Économique (ENSAE) and the École des Ponts. This project seeks to create a unified Master's-level economics school in Paris. International partnerships The Scuola Normale Superiore in Pisa was founded in 1810 as a branch of the École normale supérieure by Napoleon and later gained independence. ENS and its Italian twin have retained very close links since this time and since 1988 a special partnership has 80 normaliens going to Pisa every year while half the class of the SNS spend a year at the Paris school. During its history