The Zeppelin-Staaken Riesenflugzeuge (IPA: [ˈtsepːelin ˈʃtaːken ˌʀiːzenˌfluɡˈtsɔjɡe]) were a series of very large bomber aircraft - Riesenflugzeuge ("giant aircraft"), usually powered by four or more engines, designed and built in Germany from 1915 to 1919.