Possible Clues:

• Roman general who conquered much of Britain
• Roman general provides a king with one drink
• Gnaeus Julius --, Roman general 40-93AD
• General anaesthetic greatly regretted, inebriates each opening a drink
• Roman general and governor of Britain
• Old general I pass invading Indian city
• First-century governor of Britain, whose name was Latin for 'farmer'
• Roman has drink with Greek in perfect setting
• Roman general and governor of Britain from 78 to 84
• Recalled song about officer following a grand Roman general