A good point Nigel - those who rule write the records and the history whilst those who don't are largely invisible to us. At the time of surname adoption Manx and Scottish Gaelic were much closer to the Irish of the time than the written version we now accept as 'Manx' - mac must have remained in the vernacular language, even if it was mentioned less in the official records.

Frances, you may well be right on the change being a Tudor phenomenon. The Manorial Records show a spread of Manx C, K and Q surnames mixed with older forms using mac and ine - the Elizabethan plantations must have generated significant pro/anti-Irish positions in England - or resurrected previous attitudes from the earlier struggles - and since Lancashire was so powerful, probably in the Isle of Man too.

I am not sure I am happy with the term anglicisation - true anglicisation would have led to me being called Phillips (as in the Welsh subjugation/assimilation) - whatever, certainly the process was largely complete by the earliest parish records (officially) if not colloquially.

Nigel - do you think traditional placenames may be more representative of the people's language than the surnames in the tax and ecclesiastical records?