The titles of certain roles and institutions in Bunreacht na hÉireann (the Constitution of Ireland 1937)  have their roots in Early Ireland. One of the more interesting of these from a historical standpoint is the position of ‘Tánaiste’.
In this article I firstly provide an overview of the formal role envisaged for the Tánaiste in the Constitution, also highlighting evolution in the title during the constitutional drafting process. I then briefly sketch the apparently increased political significance of the role in more recent times, followed by a synopsis of the (debated) historical origins of the title and role of the tánaise ríg, drawing on the Brehon Law tracts.
The Constitutional Dimension
Article 28.6 of the Constitution requires that the ‘Taoiseach’ nominate a member of the Government to be the ‘Tánaiste’. Along with the other members of a Government, the Tánaiste’s nomination is subject to the approval of Dáil Éireann (the Lower House of the Irish Parliament), followed by Presidential appointment.
A curious thing about the constitutional provisions governing the role of Tánaiste is that they do not specify an English language version of the title. This contrasts with the title assigned to the Taoiseach in Articles 13.1.1. and 28.5 of the Constitution, where we are told that this equates to ‘head of the Government, or Prime Minister’.
Archival papers relating to Éamonn de Valera provide some colour on precursors to the title of ‘Tánaiste’ (and ‘Taoiseach’) during the constitutional drafting process . De Valera was a prominent figure in the Irish independence movement and a key architect of the 1937 Constitution, being the first Taoiseach to serve under it (doing so again on two further occasions) and also later serving two terms as President.
From these papers, it seems that earlier drafts of the Constitution toyed with more literal Irish language versions of the title ‘Deputy Prime Minister’ – initially Leas-Phríomh Aire, subsequently Árd-Aire-Tániste, followed by Leas-Árd-Aire . ‘An Tánaiste’ then emerged  and this somewhat more ambiguous standalone title remained into the final draft of the Constitution.
A 1999 study of the Irish language version of the Constitution helped shed further light on the title:
“Tánaiste’, in the political sense, is translated [in earlier dictionaries] as ‘deputy prime minister’…giving ‘tanist, heir presumptive’…a second thing or person, a substitute or locum tenens…the next best thing; state of being second or next best” .
Ultimately, the key expectations of the Tánaiste under Article 28.6 of the Constitution are that they must either act ‘for or in the place of’ a temporarily absent Taoiseach or ‘for all purposes in the place of’ a Taoiseach who has died or become permanently incapacitated (pending the appointment of a ‘new Taoiseach’).
But whether a Tánaiste will be the longer-term successor to a ‘Taoiseachship’ is, probably wisely, left to the political arena. For instance, there is no constitutional imperative that the Tánaiste will (or must) necessarily be appointed as the ‘new Taoiseach’ should the previous Taoiseach die or become permanently incapacitated.
The Political Dimension
Coalition governments have become the norm in Ireland over recent decades, though the first ‘inter-party’ Government dates back to 1948. In these situations the usual convention is that the leader of the junior coalition party (or the largest junior coalition party in the case of a multi-party arrangement) is appointed as the Tánaiste. The role arguably became more politically visible during the 1993-1997 coalition periods which saw the creation of a distinct ‘Office of An Tánaiste’ (subsequently discontinued) within the Government administration .
Nonetheless, up until recently a Tánaiste’s role did not necessarily equate to a political heir ‘in waiting’ for the Taoiseachship. Objectively speaking, and barring an unforeseen constitutional ‘event’ under Article 28.6, the prospect of succession (at least within the same parliamentary term) was probably even less likely where a Tánaiste was drawn from a junior coalition party different from an outgoing Taoiseach’s larger party.
The formation of a three-party coalition government in 2020 marked a political evolution in the role. Under this arrangement it was agreed that the roles of Taoiseach and Tánaiste would rotate between the leaders of the two largest (similar-sized) parties in the coalition. The distinct ‘Office of An Tánaiste’ was also resurrected to support the Tánaiste in playing a ‘significantly enhanced role in day-to-day matters’ .
The incumbent Tánaiste’s role therefore embodies both the core constitutional deputising functions outlined earlier, along with a concrete political expectation of succession to the Taoiseachship proper. This is interesting when placed in historical perspective and it is to that I now turn.
The Historical Dimension
The finer details of early Irish succession to kingly and other senior-level political roles (particularly chieftainships) have been the subject of fascinating (and noisy) debates over the years. For instance, whether eligibility was restricted to specific direct male descendants of an outgoing ruler, or if it was more or less ‘open season’ within a broader dynasty related to a common ancestor, or maybe practices varied across time and place . That full debate is outside the scope of this article but at least one dimension is worth exploring here – the tánaise ríg.
Initially, it was thought that the concept of ‘tanist’ and the associated practice of ‘tanistry’ dated at earliest to the Anglo-Norman period . Tanistry was used to describe Irish patterns of succession to senior roles and associated land. It unnerved later English administrators due to its perceived procedural uncertainty, aggravated by possible ‘lateral’ claims, e.g. legitimate claims by males in an extended kin group, not just the eldest son (contrasting with ‘primogeniture’). Tanistry would thus later be weaponised in the project of embedding English ‘common law’ in Ireland .
The characterisation of tanistry as a purely later phenomenon was, however, undermined by discovery of the term tánaise in the annals, along with the old Brehon Law tract Críth Gabhlach (‘Branched Purchase’)  dated to around 700 A.D. Here it is explained: Tánaise ríg cid ara n-eperr? Arindí fris[n]aicci tuath thuile do rígiu cen chosnam fris (‘why is the tánaise ríg so called? Because the whole people looks forward to [his] kingship without opposition to him’) . The genesis of the term is unclear but it is thought to have a parallel in early Welsh law (gwrthrychiad – ‘the looker-forward, he who expects’) and may trace its roots to an older title: aire forgill frisaicci ríge (i.e. a senior-level lord ‘who expects the kingship’) .
There is also mention in Críth Gabhlach of an ‘office…of secondary leader’. This, along with comparisons to equivalent ecclesiastical offices, such as tanaise abbad (‘abbot’), have encouraged an alternative translation of tánaise ríg as simply ‘second in command’ or ‘second to’, i.e. being a deputy position without guarantee of succession . Some have thus argued that royal succession by ‘Tanistry’ was just an ideal in early Ireland and began to be practiced only in later Medieval Ireland . A deputising tánaise ríg without automatic rights of succession may nonetheless have performed important legal functions on behalf of the túath, like acting as a personal guarantor of treaties with other túatha .
Another line of thinking has been that the tánaise ríg was functionally equivalent to a different title found in the annals – rígdomnae or damnae ríg (‘material of a king’), leading some to view these interchangeable titles as the ‘designated heir’ . Others reckon they came to signify ‘eligibility’ to succeed or consolation titles but did not, in themselves, dictate the ultimate successor, which rested moreso on raw power dynamics . There was certainly great potential for inter-dynastic tension, such as in the northwestern Kingdom of Ailech where ‘eighteen [rígdomnai] held office when a king of the opposite segment…was in power’ .
A composite analysis aimed to reconcile these different theories, concluding that there was a formal distinction between the terms damnae ríg and tánaise ríg – the first referring to all of those who were, in principle, eligible to succeed and the second referring to the ultimately successful claimant ‘once the argument was over’ . In this interpretation the main factor influencing the choice of king etc. and the tánaise ríg was a candidate’s febas (‘worth’, ‘personal standing’), itself a fluid thing .
If febas alone was insufficient to determine the outcome, the compromise may sometimes have been a rotation of the senior office between equally qualified ‘branches’, referred to as cúairt for gabla fine (‘a circuit upon the branches of the kindred’) . This arrangement is alluded to in the legal sources, albeit not a legally favoured solution . Still, there is evidence that rotation was practiced, for instance between c. 696-736 A.D. amongst the Dál Riata – an early Gaelic kingdom straddling part of today’s County Antrim and the west coast of Scotland. Here it is thought ‘the tanist [tánaise] was…the head or representative of the next dynasty in line for the kingship’ .
Early Irish procedures for inaugurating (if not designating) the tánaise, along with a new king or chief etc., may have been cloaked in a form of early ‘Celtic democracy’ derived from an ancient Indo-European heritage . Some sagas nod to aristocratic elective assemblies  and commentaries in a Brehon law tract dated to between 700 and 900 A.D., Do Astud Cirt ocus Dligid (‘On the Confirmation of Right and Law’), also lend this idea support . Reference is made there to .i. do denam comairle im gabail rige (‘council concerning the election of a chief’) .
Some concluding thoughts
The modern constitutional concept of the Tánaiste is one of a deputy but not necessarily of a longer-term successor. However, as at January 2021 the role now also embodies a concrete political expectation of succession to the Taoiseachship.
One interpretation of the tánaise ríg in Early Ireland is that it simply denoted the ‘second in command’ or ‘second to [X]’. Symbolically, this seems similar to the modern constitutional ‘deputising’ Tánaiste. But the historical tánaise ríg may also (at least sometimes) have been more than that, i.e. being the ‘designated heir’ to senior political office. If the case, it could be argued that the modern role of Tánaiste has then also symbolically come full circle in historical terms.
We also perhaps see echoes today of the historical protocol of cúairt for gabla fine (a ‘circuit upon the branches’), taking the modern form of an intended political rotation of the Taoiseach and Tánaiste roles over the coming years.
This article may be cited as J. Biggins, ‘Deputy or Heir? Origins of “An Tánaiste”‘, The Brehon Lawyer (January 2021)
Sources for this article
All-Party Oireachtas Committee on the Constitution, Bunreacht na hÉireann: a study of the Irish text (Micheál Ó Cearúil) (1999) (‘Ó Cearúil’)
Bunreacht na hÉireann, Constitution of Ireland 1937 (link)
Carine Bruy, ‘Tanaise Rig: An Alternative Interpretation’ (2002) 27 Études irlandaises 77
D.A. Binchy, ‘Some Celtic Legal Terms’ (1956) 3 Celtica 221
D. Blair Gibson, ‘Celtic Democracy: Appreciating the Role Played by Alliances and Elections in Celtic Political Systems’ (2008) 28 Proceedings of the Harvard Celtic Colloquium 40
Department of the Taoiseach, Programme for Government: Our Shared Future (29 October 2020) (link) (‘Programme for Government’)
Donnchadh Ó Corráin, ‘Irish Regnal Succession: A Reappraisal’ (1971) 11 Studia Hibernica 7
Eoin MacNéill, Celtic Ireland (Martin Lester, 1921)
Gearóid MacNiocaill, ‘The “Heir Designate” in Early Medieval Ireland’ (1968) 3 Irish Jurist 326
Ian Whitaker, ‘Regal Succession among the Dálriata’ (1976) 23 Ethnohistory 343
Immo Warntjes, ‘Regnal Succession in Early Medieval Ireland’ (2004) 30 Journal of Medieval History 377
Katharine Simms, ‘The Contents of Later Commentaries on the Brehon Law Tracts’ (1998) 49 Ériu 23
Megan McGowen, ‘Royal Succession in Earlier Medieval Ireland: the Fiction of Tanistry’ (2003-2004) 17-18 Peritia 357
Murray Smith, ‘The Title of An Taoiseach in the 1937 Constitution’ (1995) 10 Irish Political Studies 179
Robert Elgie and Peter Fitzgerald, ‘The President and the Taoiseach’ in Politics in the Republic of Ireland, eds. John Coakley and Michael Gallagher (4th edition, Routledge, 2006) (‘Elgie & Fitzgerald’)
‘The Case of Tanistry’ (1952) 9 Northern Ireland Legal Quarterly 215
T.M. Charles-Edwards, Early Irish and Welsh Kinship (Clarendon Press, 1993)
 Bunreacht na hÉireann
 Smith, p. 181
 Smith, pp. 181-182
 Ó Cearúil, p. 420
 Elgie & Fitzgerald, pp. 321-322
 Programme for Government, p. 123
 Warntjes, pp. 377-381
 MacNéill, p. 142
 Case of Tanistry
 Binchy, pp. 221-223
 Binchy, p. 222
 Binchy, p. 221-222
 Bruy, pp. 79-80
 Bruy, pp. 91-92
 Ó Corráin, p. 37
 Ó Corráin, pp. 34-35
 Charles-Edwards, p. 108
 Charles-Edwards, p. 100
 Charles-Edwards, p. 97
 Charles-Edwards, p. 97
 Whitaker, p. 356
 Gibson, pp. 61-62
 Gibson, pp. 48-50
 Simms, pp. 35-37
 Simms, p. 37