Ecgberht, King of Kent. Ca AD 765-785. AR Penny. 0.96 g. Canterbury mint. Moneyer Babba. 

+EGCBERHT around Rx monogram.
B-A-B-B-A around three crosses joined by a diamond shape in the centre. 

Chick 85d (this coin); North 199; SCBI XX, 639; Lockett III, 2628 (this coin). 
Extremely rare

With permission of Spink Auction 16019, Lot 66, March 2016.