A galleass was a warship of the Renaissance that combined the sails and armament of a galleon or carrack with the propulsion and maneuverability of the oared galley. While never quite matching up to the full expectations for its design, the galleass was widely employed by the navies of the Republic of Venice and the Spanish Empire during the 16th and 17th centuries.
Distinct types of galleasses were developed concurrently under vastly different needs. Mediterranean galleasses were invented by Venice during the OttomanāVenetian wars with the aim to overpower galley fleets, a model also adopted by Spain and other nations after their notable role in the Battle of Lepanto. In comparison, Atlantic galleasses were designed by Spain to outmaneuver sailing ships and protect their treasure fleets, eventually evolving into rowless galleons and frigates.