Study dark period in Germany’s western province (8)
I believe the answer is:
connacht
'germany's western province' is the definition.
I can't judge whether this definition defines the answer.
'study dark period' is the wordplay.
'study' becomes 'con' (con can informally mean to study).
'dark period' becomes 'nacht' (I can't justify this - if you can you should give a lot more credence to this answer).
'con'+'nacht'='CONNACHT'
'in' is the link.
Can you help me to learn more?
(Another definition for connacht that I've seen is " Irish province".)