Yan Tan Tethera

Yan Tan Tethera is a sheep-counting rhyme/system traditionally used by shepherds in Northern England and earlier in some other parts of England and the British Isles. Until the Industrial Revolution, the use of traditional number systems was common among shepherds, especially in the dales of the Lake District. The Yan Tan Tethera system was also used for counting stitches in knitting. The words derive from a Brythonic Celtic language.

Though most of these number systems fell out of use by 1910, some are still in use. The word yan or yen for "one" in some northern English dialects generally represents a regular development in Northern English in which the Old English long vowel /ɑː/ <ā> was broken into /ie/, /ia/ and so on in Northern English. This explains the shift to yan and ane from the Old English ān, which is itself derived from the Proto-Germanic *ainaz. Another example of this development is the Northern English word for "home", hame, which has forms such as hyem, yem and yam all deriving from the Old English hām.

In order to keep accurate records (e.g. of birth and death) and to alert instances of straying, shepherds must perform frequent head-counts of their flocks. Dating back at least to the medieval period, and continuing to the present in some areas like Slaidburn, farms were granted fell rights, allowing them access to common grazing land. To prevent overgrazing, it was vitally necessary for each farm to keep accurate, updated head-counts.

Though fell rights are largely obsolete in modern agriculture except in upland areas, farms are often subsidised and taxed according to the quantity of their sheep. For this reason, accurate counts are still necessary, and must be performed frequently.

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