"Battle of Heligoland" . . "2gunboats" . . . . "Austria" . "Disputed" . . . "Heligoland" . . . . . "14 killed" . . . . . . "2 screw frigates" . "Helgoland" . "1 screwcorvette" . . "Battle of Heligoland (1864)" . . "See [[#Aftermath" . . . . . "1864" . . "Battle of Heligoland (1864)" . . "Battle of Helgoland" . "Danish blockade" . . "Prussia" . "1 frigate damaged" . . . . "naval action off Heligoland" . . . "2screw frigates" . . "1864-05-09" . "1aviso" . . . . "54 wounded" .