Mark is England's first to settle (8)
I believe the answer is:
colonise
'settle' is the definition.
(I know that colonise is a type of settle)
'mark is england's first' is the wordplay.
'mark' becomes 'colon' (colon is a kind of mark).
'england's first' becomes 'e' (1st letter of 'england').
'colon'+'is'+'e'='COLONISE'
'to' acts as a link.
(Other definitions for colonise that I've seen before include "Form a settlement in a foreign country" , "Establish a state in conquered territory" , "Populate, settle" .)