In the mid-1930s he wrote music for a notorious five-minute documentary film entitled Peace of Britain. Britten also penned a Pacifist March for the Peace Pledge Union, of which he was a prominent member.

The shadow of the Spanish Civil War and Nazism in Germany can be felt in works such as his orchestral song-cycle Our Hunting Fathers (1936). This work ostensibly concerns mankind’s relationship to animals but can be decoded as mankind’s inhumanity to his fellow man.

Ballad of Heroes (1939) commemorates the fallen members of the International Brigade in Spain. The opening movement of the Violin Concerto (1939) can be heard as a lament for Spain. Sinfonia da Requiem (1940), composed when war was ravaging much of Europe, is a proto-War Requiem. There is power and savagery of its orchestral writing until the final movement offers a wordless lullaby for peace.

Britten responded to the horrors of the Second World War through several compositions.

In 1945, Britten toured with violinist Yehudi Menuhin, visiting liberated German concentration camps, where they played to the emaciated survivors, including those of the notorious Belsen camp.  Following this visit Britten produced The Holy Sonnets of John Donne (1945).

His chamber opera The Rape of Lucretia (1946) might be viewed as a metaphor for the rape of Europe. Its Christian framework an attempt at catharsis and forgiveness between former enemies. The unimaginable destruction and loss of life after the dropping of atomic bombs on Hiroshima and Nagasaki horrified the composer. He proposed to the BBC an oratorio on the subject, entitled Mea Culpa, in 1946.

A creative artist does not exist in some insulated bubble of their own making, and Britten was evidently no exception. World events impinged on his life as much as anyone’s.

War Requiem was written under the shadow of intercontinental nuclear threat. In the UK, the first of the Aldermaston marches against nuclear weapons took place in 1958. In Europe, there was the Iron Curtain, the Cold War and the Berlin Wall. In the US, the Bay of Pigs crisis and the Vietnam War.

When in 1958 the commission to write War Requiem was offered to Britten, the commissioners gave him a relatively free hand as to what he might write. – Britten formulated a plan to set the traditional Latin requiem mass but with a twist. The twist would be to add to the mass settings of the poetry of Wilfred Owen, killed in the trenches just a week before the 1918 Armistice. But Britten went further. He realised that he could reinforce the anti-war message of Owen’s poetry and undermine the Establishment’s conventional religious responses to war by how he juxtaposed Owen poetry with the Latin Mass.

As Britten’s biographer Paul Kildea once so memorably put it, Britten was a wolf in tweed clothing. He was someone who was outwardly a conventional Establishment-type figure but who held decidedly non-Establishment views where war and violence were concerned. He was a friend of royalty, the aristocracy and politicians. At the same time, he was also a member of several pacifist organisations as well as a prominent supporter of the Campaign for Nuclear Disarmament (CND).

The immediate public and critical success of War Requiem came as something of a surprise to Britten. Despite the very public occasion of the premiere, he genuinely considered the work to be a private statement of his beliefs. Yet he could not fail to be aware of the importance of such an artistic statement in 1962.

The work’s popularity grew exponentially, aided and abetted by the fine recording under the composer’s baton. It sold 200,000 copies in under 6 months, a remarkable achievement for a piece of contemporary music.

The work’s message resonated with the prevailing Zeitgeist of the 1960s, especially among the younger generation. Performances were given across the world as the decade progressed. A BBC Proms performance from August 1964 is currently available on BBC iPlayer in grainy black-and-white. This performance marked the fiftieth anniversary of the outbreak of the First World War. Britten himself, always conducting the chamber orchestra in the Owen settings, was involved in significant First World War anniversary performances in Ypres, Berlin and the Edinburgh Festival.

To coincide with the centenary of the end of the First World War, in November 2018 ENO staged War Requiem in a production directed by Daniel Kramer and designed by Turner Prize-winning artist Wolfgang Tillmans.

Martyn Brabbins will conduct the 80-strong chorus, a children’s choir of 40 voices, the full ENO Orchestra, a chamber choir and three internationally acclaimed soloists. This will be the first time War Requiem has been staged in the UK and, poignantly, at a time when we will be reflecting not only on the tragedy of the trenches a century ago but also on the incomprehensible loss of life from wars past and present. Their production will seek to examine and process the grief, offering us all a hope for the future. The warning of War Requiem still needs to heeded.