Around ’51, Soviet camp nearly assassinated ruler (8)
I believe the answer is:
caligula
'camp nearly assassinated ruler' is the definition.
I can't judge whether this definition defines the answer.
'around '51 soviet' is the wordplay.
'around' becomes 'ca' (circa).
''5g' becomes 'LI' (roman numeral).
'soviet' becomes 'gula' (I am not sure about this - if you are sure you should believe this answer much more).
'ca'+'li'+'gula'='CALIGULA'
Can you help me to learn more?
(Other definitions for caligula that I've seen before include "Successor to Tiberius" , "Notoriously cruel Roman emperor, d. AD 24" , "imperial figure" , "Emperor after Tiberius" , "Emperor who threatened to make his horse a Consul" .)