It is said that Bouboulina joined the Filiki Etaireia, an underground organization that was preparing Greece for revolution against Ottoman rule. She would have been one of a few women, but she is not named in historical members lists. She bought arms and ammunition at her own expense and brought them secretly to Spetses in her ships, to fight "for the sake of my nation." Construction of the ship "Agamemnon" was finished in 1820. She bribed Turkish officials to ignore the ship's size; it later became one of the largest warships in the hands of Greek rebels. She also organized her own armed troops composed of men from Spetses. She used most of her fortune to provide food and ammunition for the sailors and soldiers under her command.