Assertion: shore fort | /r/HasProperty | built by usurper
Facets:
value: in an ultimately unsuccessful attempt
type: TEMPORAL
Source sentences:
text: The reasons for its construction are unclear; long thought to have been part of a Roman defensive system to guard the British and Gallic coasts against Saxon pirates, it has more recently been suggested that Anderitum and the other Saxon Shore forts were built by a usurper in an ultimately unsuccessful attempt to prevent Rome from reimposing its control over Britain.