Old Germanic race took over most of mine at end of war, by Jove! (7)
I believe the answer is:
jupiter
'jove' is the definition.
('Jupiter' can be a synonym of 'jove')
'old germanic race took over most of mine at end of war' is the wordplay.
I cannot quite see how this works, but
'over' could be 'up' (I've seen this in other clues) and 'up' is found within the answer.
This explanation may well be incorrect...
'by' acts as a link.
Can you help me to learn more?
(Other definitions for jupiter that I've seen before include "A planet; Trollope's all-powerful newspaper" , "Heavenly body" , "Planet - Roman equivalent of Zeus" , "Chief of the Gods, by Jove" , "Large planet" .)