What Roman legion was present in Northern Britain?
It depends on the time period. For many years after the invasion of 43 AD the Romans had no forces in the north By 68 AD the legion IX Hispana was based at York (Eboracum) and this was the most northerly unit. The Ninth legion was replaced under Hadrian (around 122 AD) by the Sixth. Gradually the frontier moved further and further north, eventually extending well into the Scottish glens; the legionary fortress at Inchtuthil of around 86 AD is perhaps the most northerly base (intended either for legion II Adiutrix or XX Valeria Victrix) but was barely finished when the unit was posted to Dacia.
