The following is an introduction to English:
Old English is divided into four dialects: Anglo dialect (Mercia and northumberland) and Saxon dialect, Contos and West Saxon. After the educational reform of King Alfred in the 9th century and the influence of Wessex Kingdom, West Saxon dialect became the standard written language.
The epic Beowulf was written in West Saxon, and the earliest English poem Song of Cadmond was written in Northumberland. Modern English mainly comes from Mercia, but Scottish comes from northumberland. Some short inscriptions in the early days of Old English were written in runes. In the 6th century, Latin letters were adopted and written in the form of semi-informal letters. Including the rune letters Wynn and thorn, and the modified Latin letter ETH? d？ , and ash.
Refer to Baidu Encyclopedia-English for the above information.