The different spellings seen in the earliest documents (e.g., Ybuoy, Obuoey, Ybuey, O' Bowige, O' Boughaie, O' Boo, Boee, O' Bough, Buoige, O' Buoige, Bow, Buo), or ones like them, have either been noted in Irish surname history sources as earlier Gaelic versions of Bowe and Bowes, or have been found in research as possibilites. We aren't certain that the earliest of these documentary references represent prior generations of families who later anglicized their name to Boe, Bowe or Bowes. We include them here because a connection cannot be ruled out either. Keeping in mind that the earliest documents may only represent a small sampling of contemporary individuals going by names like these, you can see that the partially anglicized versions of O Bowe, O Boe and O Bow begin emerging in in the 16th century Fiants in Limerick, Tipperary, Kilkenny and Kildare.
Bowes from the north of Ireland, an unrelated group, settled there in the 17th century from Scotland, so early records for them are unlikely to be found.
While I haven't yet seen this, one researcher indicates that the 1547 Chancery Rolls show the Bowe surname at that time predominate in Kilkenny.
The Bowe surname, as Bowe, predominates in County Leix/Queens/Laois in the 1659 “Census”, the 1848-1864 Griffith's Valuation, the 1911 Census, and even the 2010 online directory. Based on the geographic stability of surnames in Ireland, this suggests that Leix/Queens/Laois, or its environs, was the origin of the Bowe spelling in Ireland. This, however, could be distinct from their earlier clan origins.
The Boe surname predominates in Kilkenny in the 1659 “Census” but in Tipperary in the 1848-1864 Griffith's Valuation. By the 1911 Census only one Boe remained, in Antrim, presumably unrelated. Most likely the Boe all eventually became Bowe.
The Bowes surname pattern differs from Bowe. In the 1848-1864 Griffith's Valuation Bowes predominates equally in counties Kilkenny and Tipperary in the south and finds another concentration in Fermanagh in the north, indicating two founding families. The northern Bowes are known to descend from a Scottish planter named Alexander Bowes who settled in Fermanagh.