The Madness of Through

The Oxford English Dictionary records all the following as legitimate historical spellings of the word through in the manuscript era, not counting any of the forms it labels “scribal errors”:

dorow, dorth, drogh, thorgh, thorght, thoro, thoro’, thorogh, thorou, thorough, thoroughe, thorow, thorowe, thorowgh, thorowh, thorro, thorrow, thoru, thorugh, thorughe, thoruh, thoru3, thorw, thor3, thour, thourch, thourgh, thourth, threu, threw, thro, thro’, throch, throche, throcht, throgh, throght, throu, throuch, throucht, throughe, throuw, throw, throwch, throwe, throwgh, throwghe, throw3e, thru, thruch, thrucht, thruff, thrugh, thrughe, thruht, thru3, thrw, thrwch, thurf, thurgh, thurghe, thurght, thurow, thurrou, thurrowe, thur3, trogh, troght, þerh, þorch, þorgh, þorghe, þorh, þorogh, þorou, þorou3, þorow, þorowe, þoro3, þoru, þoruh, þoruhe, þoruth, þoru3, þorw, þorwe, þorþ, þor3, þour, þourgh, þourh, þourw, þour3, þour3e, þro, þroughe, þrou3, þruh, þurch, þuregh, þureh, þurf, þurgh, þurght, þurh, þurrh, þurth, þuru, þuruh, þurw, þurþ, þur3, þur3e, þur3th.

Lynch, Jack. The Lexicographer's Dilemma (pp. 169-170). 

Bloomsbury Publishing