In 1966, while researching the background to Britain's first-ever national railway strike (August 1911), I came across a minute written by Winston Churchill, then Home Secretary in Asquith's Liberal government. That year was a bad one for industrial disputes and for public order. Churchill had a penchant for ordering the army to succeed where he judged the police had failed. Strikers were shot dead by the military in Liverpool (August 15) and in Llanelli four days later.

South Wales - where a 10-month strike by coalminers had ended with their abject defeat - was seething with unrest. But in his minute of August 29, 1911, Churchill did not refer to these events. He wrote, instead, of "the 'pogrom' districts."

So it was that I first learned of the anti-Jewish riots that swept the valley communities of Monmouthshire and Glamorgan in August 1911, leading to the temporary imposition of military rule – Churchill ordered detachments of the Worcester Regiment to patrol the affected areas - and to the wholesale evacuation of Jewish families by special trains that conveyed them to the relative safety of Cardiff, Newport, Aberdare and Merthyr. These riots - a week-long orgy of attacks on Jewish property - began in Tredegar during the evening of Saturday, August 19, and spread rapidly to Ebbw Vale, Rhymney and other industrial centres of the Western Valleys. Wherever Jews could be found, the rioters struck. But was Churchill justified in referring to the totality of these attacks as a "pogrom"?" And in view of the fact that non-Jewish property was also targeted, are we justified even in calling them - in any sense - "anti-Jewish?"

The riots did not come out of the blue. Seasoned observers of the social politics of South Wales were not at all surprised at their coming, nor was there much doubt that Jews were the prime targets of the rioters.

The immediate response of the Anglo-Jewish establishment was to (a) dismiss any connection between the targets of the attacks and the fact that the targets happened to be Jews and property owned by Jews, and (b) insist that the rioters were of the "hooligan" class. Neither of these suppositions was correct. Owing to the persistence of the local police, several dozen of the "hooligans" - men and women - were brought before the courts; the records of these legal proceedings reveal the actual identities of the miscreants. Addressing the Tredegar magistrates on September 5, 1911, the prosecuting solicitor observed: "The people charged [46 in all] were not hooligans. They were people who were generally considered respectable, the majority being colliers in regular employment and the wives of colliers."

Rioters prosecuted at other centres were also described as colliers. This evidence was confirmed in a report made by the general manager of the Tredegar Iron & Coal Company to one of his directors, the Liberal MP Sir Arthur Markham and quoted by Markham in a parliamentary debate on August 22, 1911, in which the culprits were frankly described as "respectable people to all appearances" and "respectable working men".

Why did "respectable working men" - and their wives - attack the Jews, who lived peacefully in their midst as minute proportions of the general population? If members of the Anglo-Jewish establishment were reluctant to agree that the rioters were drawn from the "respectable" working classes they were infinitely less inclined to admit that Jews had been targeted for specific reasons.

Most of the Jewish adults who lived in the valleys were small-time capitalists - shopkeepers, pawnbrokers and landlords. As such they advanced credit, and it is a tribute to their ethical principles and common sense that during the miners' strike and the lay-offs at the blast-furnaces they had not sought to enforce the repayment of moneys owed to them.

But once the industrial disputes had been settled, the colliers and foundry workers saw before them the prospect of having to repay their debts.

While it is true that in the later phases of the rioting non-Jewish tradesmen were also targeted, it remains the case that the riots were anti-Jewish in their origin and intention. At Tredegar only Jewish shops were attacked, while at Ebbw Vale, the Daily News reported, "the cry of the mob was … one long denunciation of Jews." The view of the presiding magistrate at Tredegar was that "the first disturbances were no doubt anti-Jewish," and the chief constable of Monmouth, in a report to the Home Office (August 21), gave it as his opinion that there was "a determination expressed by the inhabitants [of Tredegar] to get rid of them," meaning the Jews.

There is compelling evidence that the attacks were planned. According to the Rev Harris Jerevitch, minister at the Cardiff synagogue, "There is no doubt that the attacks were planned. Some of the Jewish inhabitants were informed a day or two before the outrages that people intended to wreck and loot their shops."

The police themselves told Churchill that they had uncovered evidence of "some pre-arranged plan" to attack the Jews. So fearful was the local Tredegar constabulary for the safety of the Jews that on the morning of that fateful Saturday, August 19, it had banned the Independent Labour Party from holding a public meeting to protest against the custom of a named Jewish landlord who apparently divided cottages into two so as to obtain double rent from a single property.

The riots were, in fact, marked by a fair amount of "rich-Jew" antisemitism, of the kind that had been a feature of socialist rhetoric since the Boer War. But they also had a more sinister religious dimension that owed its origin to the anti-Jewish prejudices exhibited by the Welsh Baptist movement at that time. Once peace had been restored to the valleys, the Monmouthshire Welsh Baptist Association was asked to formally adopt a resolution expressing sympathy with the Jews. One after another, Baptist ministers in conference at Blackwood (near Bargoed) spoke against the idea. "Resolutions did more harm than good (one delegate explained) and they encouraged the Jews. There were about 100 Jews at Tredegar now (he continued), and if they had many more resolutions they would have 500 there." The resolution was never passed.

That the Jews of the Western Valleys were the victims of religiously inspired as well as economically motivated prejudice is beyond doubt. The "pogrom" refugees returned to the Valleys in due course, but memories of 1911 sank deep; at the end of the Great War most of them moved permanently to Cardiff, where I met some of their sons and daughters a half-century later. The bitterness had vanished. But the memories remained.