As a beginner to this sort of thing, I *think* I've managed to positively identify the coin below as:
Edward III 'London Mint' Long Cross Penny
Pre Treaty Issue, Series D; 1351-1361 AD.
Obverse: facing bust with legend ED[WARD]US REX ANGLI
Mintmark: Cross Pommee
Reverse: CIVIT[AS] L[O]NDON
Only thing I'm uncertain about is the mintmark. Am I right in assuming a cross pommee...?

