NOTE: This is currently a work in progress and I ask for any feedback on what I have written.
Ryan is one of the top ten surnames by population / number of people in Ireland.
It would be nice if there was a simple explanation as to the meaning of the surname Ryan, unfortunately to my knowledge there isn't.
The most likely explanation is that it goes back to a King or Chief of Idrone circa 900AD named Rian or Rien. It was around this time that the Irish began taking on surnames and it may be that it was after him his descendants began to be called, O or descendent of Rian.
We are not sure how or when exactly the O'Mulryan name came about. It is likely that it means "descendent of the followers of Rian". However, this is not certain. We will see further down in this article that the genealogies suggest they are both descended from the same ancestor circa 900AD. Although other evidence does contradict this.
Just what Rian means is not known for sure. Explanations include "Little King", "Distinguished one","of noble sayings" or "tough".
Less flattering explanations for Rian include "sluggish" and for Mul that it means "bald"!
Now we dig deeper.
Callinan in "The Four Tipperary Septs" on pg 56 includes "Rien" on a pedigree of the O'Mulrians (which he references to Mac Fibris). It doesn't give a date as to when he lived.
In Celtic Leinster by Alfred Smyth pg 128 he looks at "Rián" and his descendants the "Ua Rián". He takes his information on this lineage from the Book of Leinster.
This Rián seems to have lived in the 800 / 900s based on a date that is given for his great-grand-uncle Drongal dying in 761AD.
This ties in with the information given in Bart Jaski's genealogical tables for the Uí Cheinnselaig (the ruling family of Leinster who Rian was a member of) which gives Rian as living at 900AD. See here.
Taking Mac Fibris's Mulryan pedigree (from a start date for Crumthan as 483 and using intervals of 30 years then is likely that this Rien may have lived circa 933AD.
This would suggest they are the same person. However the next in descent from Rien on Mac Fibris table, namely William, does not appear in Bart Jaski's table.
Maurice Gleeson looks at O'Harts Pedigree of the O'Ryan's here. Again the descent is different so it is hard to known how reliable the "Rian" link is.
Further work needs to be done by checking the originals ie The Book of Leinster and Mac Firbris (which I think is based on the Book of Leinster).
Meaning of the name Rian.
Most first names have a meaning. For example my own name comes from the Germanic, "leader of his people". What Rian itself means is unclear, one surname solution given online a lot is that it is "little king". However I have yet to find the original reference for this. It is possible as Rí in Irish is King.
Dineen's Irish dictionary gives a multitude of meaning to the word Rian.
For example "A distinguished one" or "of noble sayings" or a "pathway hewn through enemies" being some interesting ones. It also gives Rian as an early Irish word for the "sea".
O'Hart gives "Rien" as Righin in the Ryan pedigree here.
He gives a translation of this as "sluggish / dilatory" but in Dineen's Dictionary Righin can also mean "tough", see here.
This seems to do the rounds on various surname websites and sounds reasonable enough until you do a search for St. Riaghan
The only reference I have been able to find to a St. Riaghan in Irelands relates to a holy well dedicated to them in Glenties in Co. Donegal.
So I think that seems an unlikely solution to the meaning of the name purely due to geography. It could make sense if St. Riaghan was venerated in either Carlow or Tipp / Limerick.
I have managed to find St Riaghan in "A Dictionary of Irish Saints" by Padraig O Riain and he describes him as follows
"Ríoghán of Kilrean (Ceall Ríogháin), parish of Killybegs Lower, barony of Boylagh, Co. Donegal. Like his brothers, Manchán Míanach, and Rodaighe, the cruimhtear (presbyter), Ríoghán son of Fáilbhe belonged to the Ceinéal Boghaine branch of Ceinéal Conaill which gave name to the Donegal barony of Banagh. Although little else is known about this saint, whose name derives from rí, 'king', his church had the distinction of being selected as a place to be visited by Suibhne Gealt after the battle of Moira (Magh Rath) in 636. At Kilrean, from his perch in a tree, Suibhne was spoken to by the 'high-king', Domhnall son of Aodh, who had emerged victorious from the battle. The feast of the 'royal presbyter' Ríoghán fell on 9 August."
So from this it seems unlikely the name relates directly to St Riaghan or St Ríoghán as he was a Saint in a different part of the country and a different time-period. However O Riain does seem to confirm that Ríoghán derives from rí or king and so that may support the translation for Rian as "Little King".
How does this relate to the Mulryans?
Firstly it is unclear whether all Ryans are of the one origin. There are a number of locations from which the surname originated. The main branches are the O'Ryans of Idrone in Carlow and the O'Mulryans of Owney & Owneybeg in Tipperary / Limerick.
Other smaller groups are the O'Mulrennans of Clanconnor in Roscommon which over time changed into Mulryan and later Ryan. O'Mulrennan is likely to be from O'Maoilbhréanainn or devotee of St. Brendan. The surname Ruane / Ruan seems also to have been changed into Ryan over the years as well. Its original origin is different and can be attributed to the Mayo & Galway areas.
It is likely that the O'Ryans or O'Mulryans were from Leinster or Laingan while the O'Mulrennans would be of Connacht origin and trace their origin to Muireadach Maoilleathan, a King of Connacht.
The O'Ryans stayed in the Leinster region and were Chiefs or sometimes styled "Princes" of Idrone, which was a tuath or later barony in Carlow / Kilkenny. Essentially they would have been local kings of a their own "country" with an overking, in their case the King of Leinster.
The O'Mulryans also seem to be of Leinster origin and according to ancient genealogies descend from a joint ancestor to the O'Ryans. Why and exactly when they left the Leinster area to head to the Tipp / Limerick border in Owney & Owneybeg is not fully known.
It is likely that if you have the surname Ryan, that you are descended from the O'Mulryans of Owney & Owneybeg. They would be the most populous branch of what later became the surname Ryan.
Mac Lysaght says this about the Mulryans (Irish Families pg145):
"Ryan's are really O'Mulryans - this earlier form of the name is, however, now almost obsolete: even in the census of 1659 in Co. Limerick Ryan outnumbers Mulryan by about four to one, and today there is not one O'Mulryan or Mulryan in the telephone directory."
Meaning of Mul
Woulfe states that Maoil or Maol generally is a descendant or follower, often of a saint. However this is not universally the case eg Ó Maoilmhín is "descendant of a polish chief" or Ó Maolaidh which means "descendant of a speckled chief". Woulfe almost substitutes it for "Chief" in these case for example Ó Maolbháin which he translates as "descendant of the white chief".
This is a bit confusing as on one hand he says it is the follower or servant of a saint and on the other a chief.
O'Growney goes with follower of a saint as the main meaning of Maoil. However it can also mean the follower of a personal name. See here. In some cases it could be just bald.
Another explanation relates to the Mul or Maol part of the O'Mulryan surname. Callinan on page 8 of "The Four Tipperary Septs" states that "The prefix Maol or Mul which signifies bald or tonsured has never been found applied to the record of the O'Ryans of Idrone, but appears universally in all references to the O'Mulryans of Owney and adjoining territories until the latter part of the 17th century when it gradually became obsolete, chiefly through the substitution of Ryan for Mulryan by Dr. Petty in compiling the Civil and Down Surveys for the Cromwellian government".
It is unlikely that it does apply to bald - there are circa 80 families with Maoil in their surname included in Woulfe's surname history (see here). Most are translated as follower, servant or chief, so bald is one of the least likely explanations.
Maurice Gleeson also looks at the Ryan surname in the key surname dictionaries and the implication they have to DNA here.
O) Ryan Ó Maoilriain is the correct form in the homeland of the great sept of Ryan, formerly Mulryan; but it is now usually abbreviated to O Riain, which is properly the name of a small Leinster sept. Ryan is by far the most numerous name in Co. Tipperary having almost four times the population of the next in order (O'Brien and Maher). For a note on the derivation of Ryan see introduction, pp. xvi-xvii. Bibl.
IF Map Tipperary (Mulryan), Carlow (O'Ryan). See Ruane.
(from Surnames of Ireland, p263)
(O) Ruane Ó Ruadháin (ruadh, red). A sept of the Uí Maine. The variant Royan is found in the same area - Gortyroyan near Ballinasloe is Gort Uí Ruadháin in Irish. Royan, however, has inevitably been sometimes changed to Ryan by absorption, notably in Co. Mayo, as also have Rouine and Ruane. MIF Map Galway."
(from Surnames of Ireland, p262)
The abbreviation IF relates to Mac Lysaght's book Irish Families, and Map Tipperary refers the reader to the map in that book on page 222 where the Mulryan name is located. The entry for Ryan in Irish Families has a lot more information:
RYAN, O'Mulrian Ryan is amongst the ten most numerous surname in Ireland with an estimated population of 27,500. Only a very small proportion of these use the prefix O. Subject to one exception, to be noticed later in this section, it is safe to say that the great majority of the 27,500 Ryan’s are really O'Mulryans – this earlier form of the name is, however, now almost obsolete: even in the census of 1659 in Co. Limerick Ryan outnumbers Mulryan by about four to one, and today there is not one O'Mulryan or Mulryan in the telephone directory. The sept of Ó Maoilriain was located in Owney, formerly called Owney O'Mulryan, which forms two modern Baronies on the borders of Limerick and Tipperary, in which counties the Ryan’s are particularly numerous today. They do not appear in the records of this territory (formerly belonging to the O'Heffernans) until the 14th century, but after they settled there, they became very powerful.
The Ryan's of Co. Carlow and other counties in that part of Leinster, are distinct from those dealt with above, though both are of the race of Cathaoir Mór, King of Leinster in the second century. These are Ó Riain, not Ó Maoilriain: the chief of this sept was lord of Ui Drone (whence the name of the barony of Idrone in Co. Carlow).
(from Irish Families p145)"
In it he states
"1) Ó MAOILRIAGHAIN, Ó MAOILRIAIN—O Mulrigan, O Mulryan, O Mulrean, Mulryan, Mulroyan, Mulryne, Mulrine, Mulrain, O'Ryan, Ryan; 'descendant of Maolriain' (follower of Riaghan or Rian); the name of a family of Leinster origin who settled in the 13th or 14th century in Uaithne-tire and Uaithne-cliach, now the baronies of Owney, in Co. Tipperary, and Owneybeg, in the east of Co. Limerick, where they became very numerous and powerful. In 1610, William Ryan surrendered to the king all his landed property and all his rights of or in the barony of Owney O Mulrian, and received them back by letters patent. The family property was, however, lost in the confiscations of the 17th century. There are many very respectable families of the name in Tipperary and Limerick, and the name itself is very common in these counties.
2) Ó RIAGHAIN, Ó RIAIN—O Rian, O'Ryan, Ryan: 'descendant of Riaghan,' or 'Rian'; the name of a Carlow family who were lords of Uí Dróna, the present barony of Idrone, and are now numerous through Leinster; to be distinguished from Ó Maoilriain of Munster and Ó Ruaidhín of Connacht, which are both now incorrectly anglicised O'Ryan or Ryan
3) Ó RUADHÁIN—O Ruane, O Rowane, O Roan, Ruane, Rouane, Roane, Ruan, Roan, Roon, Rowan, Rewan, Royan, (Ryan); 'descendant of Ruadhán' (diminutive of ruadh, red); also Ó Ruaidhín; the name (1) of an old Mayo family of the Ui Fiachrach, who possessed a district lying between Newbrook and Killeen, to the north of Ballinrobe; and (2) of an old Galway family of the Ui Maine race. No fewer than seven of the name were bishops of various sees in Connacht, in the 12th and 13th centuries. The name is still very common in that province, generally anglicised Ruane, but sometimes disguised as Ryan.
4) Ó RUAIDHÍN—O Ruyne, O Royn, O Roen, Rouine, Royan, Rowen, (Ruane, O'Ryan, Ryan); 'descendant of Ruaidhín' (diminutive of ruadh, red); the same as Ó Ruadháin, which see, both forms being used by the same family, and equally common in Connacht. Some of the name have been long settled in Leinster.
5) Ó SRAITHEÁIN, Ó SRUITHEÁIN, Ó SRUTHÁIN—O Srahane, O Shrihane, O Sreighan, O Shrean, O Streffan, Shryhane, Sruffaun, Strohane, Strahan, Straghan, Strachan, Strain, Bywater, (Ryan); 'descendant of Sruthán,' or 'Sruitheán' (diminutive of sruth, an elder, a sage, a man of letters); the name of an old Tirconnell family, the head of which was chief of Clann Snedhgile, a sept of the Cinel Conaill, seated in Glenswilly, to the west of Letterkenny, and also erenagh of Conwall in the same district. Some of the family had come southward before the end of the 16th century, probably as followers of the MacSweenys, and settled in Co. Cork, where the name is still extant, but often 'translated' Bywater, as if from 'sruthán,' a streamlet. In Co. Mayo, it is sometimes strangely anglicised Ryan."
O'Hart only gives a small mention of the suranme Ryan in his book "Irish Pedigrees; or, The origin and stem of the Irish nation" (1892)
"THE following is a brief summary of the Irish families in Munster, beginning with the three branches of the race of Heber: namely, the Dalcassians, the Eugenians, and the Clan Cian.
VII. Of the Leinster Milesians of the race of Heremon, were some chiefs and clans of note in Munster, as O'Felan, princes of Desies in Waterford; and O'Bric, chiefs in Waterford; O'Dwyer and O'Ryan, chiefs in Tipperary; and O'Gorman, chiefs in Clare.
(from Chief Irish Families of Munster)
THE following accounts of the Irish chiefs and clans of Ossory, Offaley, and Leix, have been collected from the Topographies of O'Heeran, O'Dugan, O'Brien, O'Halloran, and others:—
30. O'Ryan and O'Felan were ancient families of note in Kilkenny, as well as in Carlow, Tipperary, and Waterford.
(from Irish Chiefs and Clans in Ossory, Offaley, Leix"
John Grenham on his website gives a number of explanation but they don't deviate much from the above.