Historian in press register digesting English verse (11)

'historian' is the definition.
(historian of the Middle Ages)

'press register digesting english verse' is the wordplay.
'press' becomes 'media' (the press is part of the media).
'register' becomes 'list' (listing is a kind of registering).
'digesting' is an insertion indicator (inserted letters are eaten or ingested).
'english verse' becomes 'ev' (this might be a standard abbreviation of which I'm unaware).
'media'+'list'='medialist'
'medialist' going around 'ev' is 'MEDIEVALIST'.

'in' is the link.