Early intelligence for English king: northern flier approaching border (13)

'early intelligence' is the definition.
'foreknowledge' can be an answer for 'intelligence' (thesaurus). I am not certain of the 'early' bit.

'english king northern flier approaching border' is the wordplay.
I cannot quite understand how this works, but
'english' could be 'e' (abbreviation) and 'e' is located in the answer.
'king' could be 'r' (r is abbreviation for rex) and 'r' is present in the answer.
'northern' could be 'n' (abbreviation e.g. N. Ireland) and 'n' is located in the answer.
'flier' could be 'owl' (owl is a kind of birdanimal) and 'owl' is located in the answer.
'border' could be 'edge' ('edge' can be a synonym of 'border') and 'edge' is found in the answer.
This explanation may well be incorrect...

'for' is the link.

Can you help me to learn more?