Was the British expedition about crisis or loyalty?

The review considers why Severus personally intervened in Britain late in life. Restored forts, a new granary, repairs along Hadrian's Wall, and a victory dedication suggest that Roman authority had recently been recovering in the north. Herodian nevertheless depicts a sudden emergency serious enough to bring the emperor and a large army to the province. Another interpretation treats the expedition as a way to reassert authority over a politically suspect British army after Albinus, although the delay since Severus's earlier wars counts against loyalty as the sole motive. The northern threat and the emperor's political needs may both have mattered.