Page "Medieval Latin" Paragraph 32

* The diphthong ae is usually collapsed and simply written as e ( or e caudata, ę ); for example, puellae might be written puelle ( or puellę ).

The same happens with the diphthong oe, for example in pena, Edipus, from poena, Oedipus.

This feature is already found on coin inscriptions of the 4th century ( e. g. reipublice for reipublicae ).

Conversely an original " e " in Classical Latin was often represented by " ae " or " oe " ( e. g. " aecclesia " and " coena " )