ðɪs slˈoʊli dɪvˈɛləpt fɹʌmðə fˈɪfθsˈɛntʃɚɹi fˈɔːɹm ɹᵻzˈɛmblɪŋ ðə ɡɹˈiːk lˈɛɾɚ tˈaʊ ɪnðə hˈændz ʌv mˈɛdɪˌiːvəl ˈaɪɹɪʃ ænd ˈɪŋɡlɪʃ ɹˈaɪɾɚz.
This slowly developed from the fifth-century form resembling the Greek letter tau in the hands of medieval Irish and English writers.