Emperor overwhelmed by part of Soviets' army (4)
I believe the answer is:
tsar
'emperor' is the definition.
(I've seen this before)
'of soviets' army' is the wordplay.
'of' indicates the answer is hidden within the clue.
'TSAR' can be found hidden inside 'soviets army'.
'overwhelmed by part' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for tsar that I've seen before include "Powerful man" , "Rats (anag)" , "Male monarch" , "Old Russian 22" , "Despot" .)