Segestes was a nobleman of the Germanic tribe of the Cherusci involved in the events surrounding the Roman attempts to conquer northern Germany during the reign of Augustus and then Tiberius.
In AD 9 he warned the Roman governor Publius Quinctilius Varus of the impending uprising of his countrymen, but he was not believed.
[1] Varus and his three legions subsequently perished in the three-day Battle of the Teutoburg Forest, where several allied German tribes under the command of Arminius ambushed them.
Segestes openly turned against Arminius when Germanicus invaded northern Germany in AD 15 in a renewed attempt to establish Roman rule in the area.
[2] Thusnelda was taken to Rome and, together with her brother Segimundus, displayed in Germanicus' victory parade in AD 17, with her father as an honoured spectator.