Religious Sects in Medieval Ireland

[Valnorran]

I was reading a bit on the origins of the Malones (the Irish part of my family) and discovered the first one was related to Rory O'Connor who converted and adopted the tonsure hairstyle to show his devotion to his new religion. The trouble is nothing I've read says whay he converted from. This was 12th or 13th century. I was under the impression Catholicism had become the order of the day in Ireland long before this time. Can anybody recommend some reading to shed some light on the religious scene in 12th - 13th century Ireland?

[Tiberias]

It's probably a reference to the whole debacle over the Laudabiliter Bull. Essentially, the Irish Church had never been completely in line with Rome on a handful of issues, notably the connections between noble families and the running of monasteries (which the Church frowned upon by the 12th century because it severely hindered the Church's ability to order its own employees about) and certain aspects of liturgy and ritual (the most relevant here being a variant tonsure - cutting the hair above the forehead rather than the Roman tradition of a halo-style tonsure).

http://en.wikipedia.org/wiki/Laudabiliter

"Sect", in this case, is referring to a variation within the Church.

[Valnorran]

Thanks.