The Cultural MicroBlog Contextualization (CMC) Workshop provides a collection of tweets on cultural events related to festivals. Given the size of a tweet, the information obtained by a single post is often very partial. We develop the idea that using a set of tweets about an event could enable having a more complete view of that event by combining all information posted. In this paper, we propose a model to represent the collection of microblogs into a knowledge base. Considering the set of tweets on festival events from CMC, we de ne a domain ontology and show how to populate this ontology based not only on the tweet collection but on external data too. We detail how the knowledge base could be used to provide a complete view of an event. This paper presents the preliminary results.