Abstract : What is the on-line echo of the commemoration of the centenary of the 1st World War ? What is the behavior of Memorial/Heritage Institutions about the 1st World War on Twitter ? How do they pass information about the Centenary ? Is there an effect of the English predominance on Twitter about the Centenary on the way non-English twitter accounts are considering the 1st World War? Those questions are to be answered by a research project that is to be presented in this poster, which aims at harvesting tweets containing hashtags linked to the Centenary since April 2014.