<P> Relevant dates include 117 CE , when the Empire was at its greatest territorial extent , and the accession of Diocletian in 284 . Irreversible major territorial loss , however , began in 376 with a large - scale irruption of Goths and others . In 395 , after winning two destructive civil wars , Theodosius I died , leaving a collapsing field army and the Empire , still plagued by Goths , divided between his two incapable sons . By 476 when Odoacer deposed the Emperor Romulus , the Western Roman Emperor wielded negligible military , political , or financial power and had no effective control over the scattered Western domains that could still be described as Roman . Invading barbarians had established their own power in most of the area of the Western Empire . While its legitimacy lasted for centuries longer and its cultural influence remains today , the Western Empire never had the strength to rise again . </P>
who defeated the last remaining roman army in europe
Goths