The story was a popular one in Donizetti’s day, and it’s still in the history books on both sides of the Channel, kept fresh by Rodin’s 1889 sculpture “The burghers of Calais”. After a year of siege by the English King Edward III, the walls of Calais still hold strong, but the people are exhausted and starving. Eventually, a compromise is agreed: the people will be spared from general slaughter if they send six eminent citizens to their deaths.

Il assedio di Calais (The siege of Calais) opens in the English camp outside the city walls, with Edward railing against the intransigence of the defenders. It’s a good curtain raiser, with Edward sung excellently by Grant Doyle. His voice is expansive, full of bluster and accomplishes the bel canto goal of putting across character and expression while remaining beautiful in line and timbre. But the opera really comes to life when the camera switches to the inside of the city, in which Donizetti and librettist Salvatore Cammarano fashion a vivid portrait of the febrile atmosphere. Fear, hunger, anger, despair, mistrust of strangers, hope, love and solidarity combine in a potent brew; the ETO chorus may be relatively small but they sung their hearts out, immersing us into the daily life of the besieged.

Opera doesn’t usually give true marital love much of a look in, preferring the sighs and travails of the unrequited version. Fidelio is the only example that leaps to mind in which the standard repertoire truly celebrates the strength and beauty of a loving marriage. I can now add Il assedio di Calais to my mental list: the duet at the beginning of Act II between Aurelio and Leonora was heartfelt and supremely touching. Aurelio is a trouser role (there was a shortage of top class tenors in Naples when the opera was written). The duet was sung here by mezzo Catherine Carby and soprano Paula Sides, who achieved that magical soaring of blended voices that keeps you coming back to bel canto.

Another unusual feature of this opera is the role of Eustachio, the Mayor of Calais: here is an opera in which the baritone is a truly heroic figure, who is the principal figure on stage for a high proportion of the action. Eustachio is now an old man, but he is a true paterfamilias replete with the virtues of leadership, patriotism and humanity. Craig Smith brought weight and richness to the role, especially powerful in his lower register, always smooth and expressive.

Conducted by Jeremy Silver, the orchestral performance was an unusual combination of collective excellence and individual error. In the ensemble pieces, the phrasing and pacing hit the spot precisely, allowing fairly regulation Donizetti fare to create an impact far beyond what you might have expected. Joined with the enthusiasm and punch of the chorus singing, the big set pieces really impressed. Individual wind playing, however, was jittery: when the orchestration thinned out, there were quite a few missed or cracked notes.

James Conway’s modern dress staging is a straightforward, unfussy affair: fatigues for the English, ragged patched up whatever for the embattled French, the landscape formed mainly of a giant pipe of concrete, half shattered. It’s not a staging that will stay in the memory, but it succeeded in creating the oppressed atmosphere.

Conway considers Act III of Il assedio di Calais (in which Edward’s Queen persuades him to spare the lives of the six burghers, as happened in real life) to be thoroughly unsatisfactory, supported by the fact that Donizetti thought the same and had planned to rewrite or remove it. This production dispenses with Act III altogether, moving its most compelling music to Act I and getting rid of the rest. It leaves the opera a shade on the short side at just 95 minutes of music, but Conway has a strong argument that dramatic integrity is improved as a result.

And certainly, this production of The siege of Calais is greater than the sum of its parts. There’s plenty of high quality singing to delight the ear, with a lot of emotion coming through in a piece that’s far from the standard operatic love triangle convention. Written half a century before the verismo movement, its true-to-life portrait of a besieged people left me genuinely touched. I'm very glad to have seen it.