91-form timeships, also called the Ships of War, were created by the Great Houses during the years immediately before the War. Though not recognisably intelligent, the minimum-intensity biodata in their structures gave them a biological edge, suggesting they were aware of life on their pilots' level.
91-forms were also the first timeships designed to be indiscreet, appearing as consistently big, bulky, and unapologetic. In orbit, they were often mistaken for arks or flagships of lesser species; however, they more often rooted themselves on planets at ground level, pushing aside buildings and taking the forms of giant cathedral-like embassies for the Great Houses. Some such grounded 91-forms were incapacitated or abandoned and dug out of the group millions of years in the localised future, misidentified by the natives as relics of a lost civilisation or the bones of huge, semi-mechanical monsters.
House Mirraflex used 91-form variations in their assault on the City of the Saved. (PROSE: Timeships)
Valentine Bregnan obtained Red Uranium from the Black Man to build a bomb to destroy a Ship of War buried under his town. (PROSE: This Town Will Never Let Us Go)