THERE is a double celebration going on right now among British Jews. First is the festival of Chanukkah, which celebrates the Maccabees ousting the Graeco-Syrians from Jerusalem in 165BC and restoring Jewish independence.

It was as much a spiritual victory as a military one, for the Land of Israel had been under foreign control for centuries and the Macabees only revolted when there were attempts to eradicate Judaism as a religion by Hellenising it. Chanukkah therefore carries strong themes of standing up for one’s faith and resisting assimilation.

This raises potentially awkward questions about the second celebration: the 350th anniversary of Cromwell’s decision to readmit the Jews to Britain, which he took in 1656. Would the challenges posed by tolerance prove as threatening as the dangers arising from persecution? Jews had lived here much earlier, but had been expelled by Edward 1 in 1290, partly because of the Church’s campaign against them as enemies of God, and partly as they were of no use to the King, economically ruined by decades of royal fines and levies.

As a Puritan, Cromwell paid as much attention to the Old Testament as the New, and had great regard for the Children of Israel and their descendants. He was also keen to give a firm economic basis to his New Commonwealth, and welcoming Jewish merchants was one way of achieving that aim.

The 350 years since then can largely be described as “steady progress”. While Jews on the Continent were forced to live in ghettos and subject to humiliating social restrictions, British Jews had freedom of residence, few bars on their chosen occupations and the full protection of the law. A later wave of Jewish immigrants fleeing persecution in Eastern Europe in the 1880s caused some concerns over the “alien invasion”, but they quickly became anglicised and formed a vibrant part of British life.

They included the barrow boy Jack Cohen who founded Tesco and the market trader Michael Marks, who partnered Thomas Spencer to form M & S. Some helped to enrich the English culture to which they were relatively new, such as the playwright Harold Pinter, the philosopher Isaiah Berlin, the poet Danny Abse and the impresario Lew Grade.

Others became immersed in political life, and eventually represented wider society in Parliament. Moreover, they crossed all political boundaries, with Labour MPs such as Manny Shinwell and Ian Mikardo, Liberal MPs Rufus Isaacs and Herbert Samuel; while at one point Margaret Thatcher had five Jewish members in her Cabinet.

Another wave of Jewish immigrants sought refuge from Nazi Germany in the 1930s. The result was that Britain benefited from the diverse talents of the Nobel prizewinner Ernest Chain, the artistic director Jonathan Miller, the statistician Sir Claus Moser and the healthcare expert Baroness Neuberger.

There are occasional incidents of anti-Jewish prejudice and some Jews worry that, with memories of the Holocaust waning, anti-Semitism is now less politically incorrect than before. Others point out that there is no institutional anti-Semitism, as became clear when the Conservative Party elected Michael Howard as its leader.

The transition from alien immigrants to acculturated members of society within two generations has been breathtaking, a tribute both to Jewish industry and British tolerance. However, it has led to fears that a high level of integration will damage Jewish life, leading to a loss of identity and the collapse of communal structures. One example is the rate of intermarriage, with almost 50 per cent of Jews today marrying non-Jews. If, as many assert, it leads to a dimunition of Jewish life and to Jewish traditions not being passed on to the next generation, it might be the kiss of death.

A more positive analysis suggests that intermarriage need not be seen as someone “marrying out”, but of someone “marrying in”. If the community is more welcoming to non-Jewish spouses, Jewish partners will be more inclined to remain within the fold and a doomsday scenario can be averted.

Another response has been the leap in the number of Jewish day schools that have developed in the past 20 years. The hope is that they will provide the positive Jewish identity that many Jews lack and that parents are unable to provide for the next generation.

But other Jews oppose such moves, seeing faith schools in general as the wrong route for British society, resulting in children from different backgrounds being segregated, with society fragmented as a result.

Another dramatic change has been the religious pluralism that has evolved within the Jewish community. Whereas Orthodox Judaism once dominated, now British Jewry has Reform, Liberal and Masorti movements. Generically known as “Progressive” synagogues, they each seek to marry the best of tradition with the realities of modernity, varying in the respective weight they give to either aspect.

The Chief Rabbi is a well-known figure, but two Reform rabbis have achieved national prominence through their involvement in religious broadcasting. Lionel Blue’s Thought for the Day has helped wake up listeners to Radio 4 and start their morning with a smile, while Hugo Gryn’s wit and wisdom illuminated controversial issues on the station’s popular programme The Moral Maze.

To the surprise of many, not only is the Progressive wing growing, but so is the ultraOrthodox. This is partly because of their high birth rate, but also because of a return to greater traditionalism by some Jews who have become disillusioned by what secular culture has to offer.

For them the festival of Chanukkah reinforces the need to resist popular trends and concentrate on a more meaningful way of life, rooted in the values of old. Marry the Zeitgeist, they warn, and you will end up a widow.

Despite this claim, the majority of the community prefers to engage with wider society, even if it means a delicate balancing act between Jewish life and contemporary mores, neither isolating themselves from their neighbours nor forgetting the Jewish identity that the Maccabees fought to keep alive.

For now, though, British Jews will simply enjoy a very special birthday party: 350 years young.

Rabbi Dr Jonathan Romain is minister of Maidenhead Synagogue and author of The Jews of England