When did the process occur that occurred after the futhorc runes are thought to have been developed, resulting in the Anglo-Saxon runes to also being called the Anglo-Frisian runes?
Anglo-Saxon runes: Anglo-Saxon runes are runes used by the early Anglo-Saxons as an alphabet in their writing. Anglo-Saxon runes:  The characters are known collectively as the futhorc (or "fuþorc"), from the Old English sound values of the first six runes. Anglo-Saxon runes:  Since the futhorc runes are thought to have first been used in Frisia before the Anglo-Saxon settlement of Britain, they have also been called Anglo-Frisian runes. Anglo-Saxon settlement of Britain: The Anglo-Saxon settlement of Britain describes the process which changed the language and culture of most of what became England from Romano-British to Germanic. Anglo-Saxon settlement of Britain:  This process occurred from the mid-fifth to early seventh centuries, following the end of Roman power in Britain around the year 410.
mid-fifth to early seventh centuries