Peep into not so historical centre of poetry (6)
I believe the answer is:
Here is my best explanation:
'historical centre of poetry' is the definition.
I can't judge whether this definition defines the answer.
'peep into not' is the subsidiary indication.
'peep' becomes 'bo' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'into' indicates putting letters inside.
'not' becomes 'less' (I've seen this in other clues).
'bo' placed into 'less' is 'lesbos'.
'so' is the link.
(Other definitions for lesbos that I've seen before include "From island", "Greek island -- home of 3", "Jot", "Island, home of Sappho" and "Greek island, birthplace of Sappho".)