This “journal-first” paper summarises a publication by the same authors in the journal Logical Methods in Computer Science which describes a formal semantics for the Event-B specification language using the theory of institutions. It defines an institution for Event-B and shows how the constructs of the Event-B specification language can be mapped into our institution. This algebraic semantics distinguishes three constituent sub-languages of Event-B: the superstructure, infrastructure and mathematical languages. An important impact of this work is that our semantics provides access to the generic modularisation constructs available in institutions, including specification-building operators for parameterisation and refinement. We demonstrate how these features subsume and enhance the corresponding features already present in Event-B through a detailed study of their use in a worked example. Further benefits of the institutional approach are its provision for mathematically definable interoperability to facilitate heterogeneous specification.