When the 20th century began, the renovation or foundation of institutions for the advancement of science, mathematics in particular, was promoted in Spain:

1900: Ministry of Public Instruction. Educational reform

1907: Board for Advanced Studies and Scientific Research (Spanish acronym JAE)

1908: Spanish Association for the Advancement of Science (AEPPC)

1911: Spanish Mathematical Society (SME)

1915: Mathematical Laboratory and Seminar of the JAE

The Royal Spanish Mathematical Society (RSME, at its beginnings SME) celebrated its first centenary with numerous activities throughout the year 2011, including the publication of the book History of the Royal Spanish Mathematical Society (in Spanish) written by L. Español. It contains Preamble: Before the RSME, where E. Ausejo, F. Vea and M.A. Velamazán collaborate with the author to briefly describe the institutional context prior to the founding of the RSME. During the last third of the 19th century the Spanish mathematical community was poorly developed and most of its members were either civil engineers or military of the technical specialties of the Army and Navy. Mathematics teachers of high school and university were becoming more numerous but had less social influence than engineers and military. In founding the RSME they played an important role three professionals in the capital Madrid: the military M. Benitez, who proposed at the first congress of the AEPPC the establishment of the Society, the engineer J. Echegaray, who was its first president, and the full professor C. Jiménez, who was the first director of the social journal Revista de la SME.

Over the years, the evolution of Spanish society and its community of mathematicians led the RSME to crisis of varying lengths that ended with a kind of refounding:

1919: First refounding guided by J. Rey Pastor, after the crisis held in 1917.

1941: Refounding by the Dictatorship, after the Civil War 1936-39.

1961: Refounding in parallel to the First Development Plan, after a generational crisis.

1997: Last refounding, after a deep crisis that began in 1990.

The aim of my contribution is to draw a selective picture of the RSME’s history focused on its founding and the refoundings which have occurred over its first hundred years of life.