The 1911 Congress Internationale des Ephemerides was held in Paris. Following the earlier conference held in 1896, the five principal ephemeris-producing nations (France, Germany, Great Britain, Spain and the United States) agreed to co-operate in the production of almanac data, with the aims of avoiding duplication of effort and of standardising the basis upon which the ephemerides were computed. Thus each office was allocated a set of similar computations, which were to be circulated to all the other offices. This arrangement came fully into force in the publications for 1916. This cooperation was further strengthened with the creation, in 1919, of the International Astronomical Union (IAU), where all became members of Commission 4 on Ephemerides.