‘Nothing remains more vividly in my mind, looking back on my years in No. 10, than the eleven weeks in the spring of 1982 when Britain fought and won the Falklands War,’ wrote Mrs Thatcher in her memoirs. ‘Much was at stake: what we were fighting for 8,000 miles away in the South Atlantic was not only the territory and people of the Falklands, important though they were. We were defending our honour as a nation, and principles of fundamental importance to the whole world – I do not think I have ever lived so tensely or intensely as during the whole of that time.’

Though of strategic importance, even Lady Thatcher acknowledged ‘the Falklands were an improbable cause for a twentieth-century war’. 1983 was to mark the 150th anniversary of the beginning of British rule there and believed to have been a trigger for the Argentine Junta, despite the islanders’ preference to remain British through the principle of ‘self-determination’, established in international law and UN Charter alike.

Argentina’s military regime had been in place since December 1981 and struggling with economic stagnation alongside civil unrest. Talks over the status of the Falklands had been ongoing for some time but the Buenos Aires decided to short-circuit matters. Alleged scrap-metal dealers raised the Argentine flag on the remote island of South Georgia on 19 March. A Royal Naval vessel was dispatched to investigate and on 2 April the Junta ordered a military invasion of the Islands. By this time further British forces were on the way to strengthen the presence and upon arrival found themselves at war.

Diplomatic support from the United States helped. After several battles, the Argentine surrender came on 15 June. The conflict brought about 11,000 captured Argentine troops, with the death of 255 British servicemen, 649 Argentines, and three Falkland Islanders. It prevented Argentina from going to war with Chile and facilitated the return of a democratic government there in 1983, with full British citizenship restored to the islanders at the same time. In the UK it gave the Tory government a bounce, Mrs Thatcher much personal kudos, and a significant win in the 1983 general election.

For Eliza Filby in her book God & Mrs Thatcher ‘the beginnings of the tense relations between the Thatcher government and the Church of England [can be traced to] the fallout over the Thanksgiving Service for the Falklands War in St Paul’s Cathedral in July 1982’. Here the politics of Church and State brought the key players into conflict themselves. The left-wing Dean of St Paul’s, Alan Webster, was more keen on a ‘reconciliation’ service than ‘thanksgiving’. Cardinal Basil Hulme was also consulted for the RCs and had already objected to it being about ‘liberation’, mindful of the prevalent theology at that time. Mrs Thatcher was keen not to take part in the service herself but wanted full involvement for the armed forces – not least because a parade and colours to the altar were not allowed. She did not want to read a lesson, as suggested, and questioned the idea she say a formal farewell to the Queen at the west door.

Suggestions that up to half the service be in Spanish, or at least the Lord’s Prayer, did not play well. The Bishop of London was Graham Leonard and someone the Prime Minister trusted. He avowed to her privately that ‘even with the form of service agreed, there was no guarantee that the Dean of St Paul’s would follow it’ according to Charles Moore, her official biographer. Leonard advised her to seek the intervention of Archbishop Runcie or even the Queen; a potentially Erastian dilemma.

Runcie’s sermon was emphatic: ‘War is a sign of human failure’. Denis Thatcher later the same day is reported to have said ‘The boss was livid’ but Runcie told Moore ‘She gripped my hand and said “Well done”.’ The Queen summarized it correctly: ‘I don’t think you should ever leave a Christian service feeling sad’. Mrs Thatcher felt ‘because of the presence of the Queen and all the Royal Family…the military band, trumpeters, the service was a great comfort to the bereaved and that mattered more than anything else’.

The service can be seen to have established two key principles in national religious events and celebrations. The first being their ecumenical character which has continued to be so ever since. The second was the more nuanced element of how the Church might preach the Gospel so publicly in the face of a political agenda or secular preconceptions. (The sermon given by Bishop Chartres at Lady Thatcher’s own funeral under the same dome being a case in point.) This moved on from Runcie’s ‘fairytale wedding’ romanticism at the 1981 royal wedding to a more serious engagement with public policy. The 1985 Faith in the City report took serious issue with the Conservative government for increasing spiritual and economic poverty in cities, and set Urban Priority Areas for urgent focus.

Mrs Thatcher had her triumphal note with a City of London victory parade in October 1982. Her preference for George Carey as the next +Cantuar was seen as snub to the previous Lambeth regime. From 2007, Gordon Brown delegated episcopal appointments to the CNC; a different and questionable form of self-determination.