The Massacre of Lisbon
Wednesday marks the 500th anniversary of the Massacre of Lisbon, in which more than four thousand Portuguese Jews were killed over the course of three days (April 19-21, 1506). A memorial of sorts may be held in the Rossio; see Rua da Judiaria [in Portuguese] for more details.
See Wikipedia for some information about the massacre in English, or read The Last Kabbalist of Lisbon.