Much has been made of Charles Haughey's meeting with Margaret Thatcher at Dublin Castle in 1980. Too much, perhaps. The Anglo-Irish summit was unusual in that heavyweight British ministers attended - Lord Carrington, the architect of the Rhodesian settlement, and Sir Geoffrey Howe among others - but the promise was not borne out by results.
If Garret FitzGerald, Albert Reynolds, John Bruton and Bertie Ahern tugged forelocks at various times in the direction of that Dublin Castle meeting, it was done for political insurance purposes. The suggestion being that Mr Haughey, with his "green" nationalist credentials, had initiated a new phase in Anglo-Irish relations that they were merely developing.
Dublin Castle, where Mrs Thatcher had slept overnight, produced a communique which, for the first time, spoke of addressing the "totality of relations" within these islands.
It was a ringing phrase, which meant as little, or as much, as was required by the speaker. And, within days of its appearance, the British prime minister was expressing fury over its interpretation by Dublin ministers. From there, it was all downhill for Mr Haughey's governments as Anglo-Irish relations soured over the death of H-Blocks hunger-strikers and the Falklands war.
Mr Haughey blamed the loss of a general election in 1981 on British policy concerning IRA prisoners. And, to guard Fianna Fail's flank against the growth of Sinn Fein in the South, he adopted a strongly nationalist approach. As the years passed, Mr Haughey reclaimed his role as the bete noire of the British establishment.
The next Taoiseach to urge change on the British government was Garret FitzGerald. Taking a more moderate approach than Mr Haughey, he sought to devise alternative nationalist strategies through the New Ireland Forum of 1983.
Its findings were brusquely rejected by Mrs Thatcher. But when the British prime minister could no longer ignore the reality that the rule of law did not operate in parts of Northern Ireland, she agreed to the security-driven Anglo-Irish Agreement of 1985.
It was a major achievement by the Fine Gael-Labour Party coalition government; grudgingly agreed by Mrs Thatcher. But it was immediately rejected by unionist politicians, by Provisional republicans and by Mr Haughey from the Fianna Fail opposition benches.
In spite of strong support from the SDLP, the deal was never implemented at local level within Northern Ireland. A unionist campaign of civil disobedience was faced down by the British government. But the core of the Agreement was a dead letter in terms of internal Northern Ireland politics. As unionists continued to say No, London and Dublin ministers co-operated in a form of direct rule.
Albert Reynolds was the initiator of the current initiative. On entering government with Dick Spring in 1992, he confided that John Hume had been in secret talks with Gerry Adams and believed there was a chance the IRA would abandon its campaign of violence if an acceptable political settlement was available.
It was the start of a convoluted talks process which culminated, a year later, in the Downing Street Declaration. That document restated the principle of consent to any constitutional change, and promised a Bill of Rights, and parity of esteem to the nationalist community. The unionists were assured that Articles 2 and 3 would be changed and that their political aspirations, within the United Kingdom, would be safeguarded.
During that time, Mr Reynolds and Mr Spring alternated in their roles as "hard cop-soft cop" as they sought to bully and entice both Sinn Fein and the Ulster Unionists towards the negotiating table. Within Fianna Fail, Mr Reynolds broke new ground by ensuring acceptance of the principle of consent, following the ambivalence of the Haughey years.
Demands from Sinn Fein for clarification of the Downing Street Declaration delayed an IRA ceasefire. In spite of increasing public criticism, Mr Reynolds kept faith with the process when most of his colleagues had given up hope. He was triumphantly vindicated when the IRA called a ceasefire in 1994.
But unionist demands for arms decommissioning stalled the talks process and Mr Reynolds's government fell late in 1994.
A new coalition, headed by John Bruton and Dick Spring, took up the task. By February of 1995, in spite of unfounded doubts concerning Mr Bruton's political toughness within Fianna Fail, they had agreed a Joint Framework Document with John Major. It was rejected as a template for a political settlement by unionists and given only conditional support by Sinn Fein.
With Mr Major increasingly dependent on unionist votes in Westminster and the political process stalled, the IRA broke its ceasefire. Within months, James Molyneaux was replaced as leader of the Ulster Unionist party by a perceived hardliner, David Trimble.
From there it was a slow, painstaking recovery process. The Bruton-Spring government invoked the help of the US and President Clinton in surmounting the decommissioning crisis with the help of Senator George Mitchell. But the price was a Northern Ireland election and a two-year talks agenda.
It took the election of a British Labour government and the appointment of Bertie Ahern as Taoiseach to inject fresh momentum into the talks. Mr Ahern began well by establishing a good working relationship with both Tony Blair and David Trimble.
The Taoiseach made room for Mr Trimble's sensibilities in relation to East-West structures and, to an extent, on North-South bodies. Power-sharing within a Northern Ireland assembly fell outside Mr Ahern's remit and had to be sorted out between nationalists, unionists and the British government. But, with the relevance of North-South bodies predicated on an assembly power structure, all elements were linked.
Yesterday bottom lines were finally reached and agreed. The political settlement will now go before the electorates, North and South, for ratification through referendums. It promises much. Its structures carry the fingerprints of party leaders going back to Dublin Castle in 1980, and beyond it to the Sunningdale Agreement signed by Liam Cosgrave in 1973.