Chief Rabbi Isaac Herzog

The Belfast Hebrew Congregation had been told to expect a polished, dapper Frenchman. What arrived, hunched over a book on the train platform in 1916, was a small, pallid man who looked as though the journey itself had used him up. Isaac Herzog did not correct the impression. He rarely needed to. The frailty was real, and so was what lay beneath it.

He had been formed in the Pale of Settlement, in a world where rigorous Talmudic learning sat inside the narrow margins the Tsarist state allowed it, and he had mastered all sixty-three tractates by the age of sixteen. From there the family moved, Poland to England to France, and the boy who could recite scripture by heart went on to take a doctorate in zoology from the University of London, studying the Murex snail in pursuit of the ancient blue dye once used to colour the tzitzit. It was not a scholar's detour from religion. It was the same mind working two ends of the same question, the lost thread of Jewish law traced through marine biology as readily as through the yeshiva.

Belfast, when he reached it, was no easy posting. The city sat at the meeting point of sectarian tension and rising nationalist feeling, and its small Jewish community, gathered around the school on Cliftonville Road, held an uneasy minority position in a city already divided against itself. Herzog's answer was not caution. He learned Irish, and learned it fast enough to address nationalist meetings in the language, and in doing so moved his congregation from suspected outsider to fellow traveller in the republican cause. Dublin took to calling him the Sinn Féin Rabbi. It was 1918 in Belfast that his son Chaim was born, a name that would one day sit at the head of the State of Israel, though that was still a long way off.

Dublin followed in 1919, and with it the Chief Rabbinate, an office that grew as the new state itself was growing. By 1926 his authority had been formally extended across the Irish Free State; by 1933, Cork, Limerick, and Waterford had accepted it too. He worked from a house at 33 Bloomfield Avenue, which became, in effect, the address of Irish Jewry itself.

The defending was constant, and necessary. Before a Seanad committee weighing the Slaughter of Animals Bill, he argued shechita was both humane and a right, and won the argument. He founded the Zion Schools in 1934 and fought Saturday classes at St Andrew's and Synge Street, insisting the Sabbath be left alone. He brought Moishe Vilensky from Vilna to raise the standard of Jewish education in Dublin, and at Bloomfield Avenue he ran Din Torah, religious tribunals that settled disputes for Jew and gentile alike — not unlike, though he may never have drawn the comparison himself, the old Brehon judges who once arbitrated Irish quarrels by custom and standing rather than by the rigidities of English law.

At home he was married to Sarah Hillman, father to Chaim and Yaacov, and by every account something of an absent-minded professor — Chaim liked to tell of him walking half of Dublin with a broken shoelace trailing behind him, entirely unaware. The same detachment showed in his giving, which ran ahead of his means often enough to leave the family £300 overdrawn at the bank. It was this unworldliness, oddly, that won him Éamon de Valera's genuine respect. De Valera called him a good and holy man, and the friendship between them did real work: when the 1937 Constitution was drafted, Herzog's hand was in the wording of Article 44, and where the Catholic Church received its special position, the Jewish congregations of Ireland received something rarer still — to be named, explicitly, as belonging.

He left for Palestine in the last months of 1936 to take up the Chief Rabbinate there, handing on a community that was, by any account, more secure than the one he had found. He had been a double patriot in the truest sense, wholly of Ireland and wholly of his own tradition at once, and he left both the richer for it.