This one of the oldest legions of Rome was created by the famous Julius Caesar for the war in Gaul and had a glorious fighting history, fighting in different parts of the Roman state. And suddenly in the II century BC. E. The legion disappeared. The year and place of his disappearance are unknown.
There are three versions, the geographic and temporal variations of which are impressive. This could happen in the 120’s in the north of Britain, during a large-scale invasion of Picts (the ancestors of modern Scots). After this, the famous Adrian’s shaft was created, separating the Roman part of Britain from the barbarian.
Either it happened in the 130s in Judea, during the major uprising of Bar Kochba, after which Jerusalem was destroyed, and the Roman colony of Elia Kapitolina was founded on its ruins. Or it could have happened in the 160s in Armenia, during the Parthian War, when an unidentified legion was destroyed. In any case, in the list of legions compiled under Emperor Marcus Aurelius in 165, this unit was no longer listed.
I must say that the Roman legion was a powerful force, its destruction was an extraordinary event and fairly well documented in the sources. The mysterious disappearance of the Ninth Legion seems mysterious, accompanied by absolute silence of the sources.