Ash (or "aesh," from Old English "æsc") (Æ æ): a ligature of "a" and "e," borrowed by English scribes from Latin and given the name of a character from the runic alphabet.
O E ligature (Œ œ), sometimes called "ethel" (from Old English "œðel," which is the name of its phonetic equivalent in the runic alphabet): a ligature of "o" and "e," borrowed by English scribes from Latin.
Yogh (Ȝ ȝ): The yogh is derived from the form of the letter <g> (ᵹ) as it appears in Insular scripts such as were commonly used in Old English manuscripts; thus in Old English this is simply the shape of the letter <g>. In Middle English manuscripts, the familiar "g"-shape is introduced by French-trained scribes, and the Insular "g"-shape (the "yogh") survives alongside it with a change of phonetic value (being either the [j] sound represented by the <y> in "yellow" or "yogh," or the [x] sound represented by the <ch> in Scots "loch" or the <gh> in "yogh": the two consonantal sounds in the word "yogh" are the two principal phonetic values that the character ordinarily represents). The name of the character is known through a passage in Mandeville's Travels at the end of Chap. 15 ("Mandeville" at several points offers observations on "foreign" alphabets): "And wee in Englond haue in our langage & speche ii lettres mo þan þei [i.e., the Saracens] haue in hir abc & þt is þ & ȝ the whiche be clept þorn & ȝogh."
Thorn (Þ þ): borrowed by Old English scribes from the runic alphabet for the non-Latin, Germanic sounds (dental fricative, voiced and voiceless) now usually written <th> (as in "though" and "thin"). The <th> digraph was introduced into English manuscripts by French scribes in the Middle English period, and eventually (towards the end of the Middle English period) the thorn fell out of use.
Eth (Ð ð): this is an invention of Old English scribes (formed by crossing the stem of a "d") for those same non-Latin sounds now written <th>. As mentioned above, the <th> digraph was introduced into English manuscripts by French-trained scribes in the Middle English period. The eth and thorn were used more or less interchangeably in Old English manuscripts, representing either the voiced or the voiceless <th>; however, the eth fell out of use in the early Middle English period (because of the redundancy) while the thorn survived to the end of the fourteenth century.
Wynn (Ƿ ƿ): borrowed by Old English scribes from the runic alphabet for a non-Latin sound, now written <w>. The <w> glyph (originally made of two "u" characters [<vv>, keeping in mind that the <u> and <v> were variant forms of the same letter], and therefore named "double-u") was introduced into English manuscripts by French-trained scribes in the Middle English period.
Eszett (ß) (or "sharp s"): not used in modern English, but it appears frequently in medieval and early modern Scots manuscripts, with its German phonetic value ("ss" or "sz," from which the name is derived).
[ Course Notes: Introduction ] | [ I. Towards a definition of "manuscript studies" ] | [ I.ii. The four branches of bibliographical study ] | [ I.iii. Topics in the social history of texts ] | I.iii.a The "Rescue" of Medieval Manuscripts from Grocers and Fishmongers | [ II. Diplomatics ] | [ III. Codicology ] | [ III.ii. Decoration and Illumination ] | [ IV. Paleography ] | [ IV.ii. Historical Notes ] | [ IV.iii. Writing Implements ] | [ IV.iv. Letter Formation ] | [ IV.v. Special Characters in English Manuscripts ] | [ IV.vi. Scribal Abbreviations ] | [ IV.vii. Punctuation ] | [ IV.viii. Paleographical sample: William Herebert, OFM (early fourteenth-century England) ] | [ Herebert sample, with transcription ] | [ Herebert sample: enlargement of full page reproduced at high resolution ] | [ V. Textual analysis (James E. Thorpe) ] | [ V.ii. Scribal error ] | [ V.iii. Kinds of edition ] | [ V.iv. Examples of over emendation on insufficient grounds ] | [ VI. Linguistic competence (an example): An Outline History of the English Language ] | [ VII. Libraries and archives: ] | [ VII.ii. British Library Manuscript Collections ] | [ VII.iii. Bodleian Library Manuscript Collections ]