Sanofi evolved through a complex series of major corporate mergers and acquisitions over several decades before establishing its current brand identity. Its lineage includes prominent historical French pharmaceutical precursors such as Sanofi-Synthélabo (which was formed via the 1999 merger of Sanofi and Synthélabo), and subsequent sweeping integration with Aventis in 2004, initially creating Sanofi-Aventis before shortening the corporate name back to Sanofi.