Absolute chronology of early sound changes reflected in Pre-Old English runic inscriptions

This article presents an absolute chronology of the early major sound changes reflected in the Pre-Old English (Pre-OE) runic inscriptions. These inscriptions were written in the Pre-fuþorc, which was still close to the Common Germanicfuþark(= Olderfuþark) of 24 characters but was extended and modified during the Pre-OE period (ca. AD 425–610/650). The Caistor-by-Norwich Brooch (ca. AD 610–650) marks the beginning of Old English (OE) because the new and modified runes –ᚩ o,ᚪa,ᛟœ,ᚨæ – with their new phonemic sound-values appear together for the first time. All the relevant sound-changes were completed by then. The Pre-OE and also the Pre-Old Frisian (Pre-OFris.) data reveal four phases of development. In my proposed chronology phases one and four are straightforward, while phases two and three are more complex, with two scenarios being possible.