Like the rest of Western Europe, medieval Wales was Christian. The clergyman and author Gerald of Wales wrote an account of his journey through Wales in 1188 in order to recruit soldiers for the Third Crusade, the Itinerarium Cambriae. In it, he makes no reference to Jews in Wales, while including an allegorical narrative concerning a Jew and a Christian priest travelling in Shropshire, England. During the thirteenth century there are records of Jews in Abergavenny, Caerleon and Chepstow, all of which were in the Marcher Lordships of south Wales. It is likely that most if not all Jews left Wales after Edward I's act of 1290, although the writ of the English king would not have run in many of the Marcher Lordships. The Welsh chronicle Brut y Tywysogion refers to the act but only in the context of the Jews in neighbouring England. There is a record of an unnamed Jew in the commote of Manor Deilo in Carmarthenshire in 1386/7.
In England, between 1290 and their formal return to that country in 1655, there are no other official traces of Jews as such except in connection with the Domus Conversorum, which kept a number of Jews who had converted to Christianity within its precincts up to 1551 and even later. There is no comparable evidence for Wales. The BBC notes, "The oldest non-Christian faith to be established was Judaism, with a presence in Swansea dating from around 1730. Jewish communities were formed in the next century in Cardiff, Merthyr Tydfil, Pontypridd and Tredegar."
Modern period
The rapid expansion of the coal mining industry in the 19th century led to major economic growth and a vast increase in immigration to Wales. The Jews immigrated to Wales in large numbers, leading to the founding of new Jewish communities, particularly in the heavily industrialized South Wales Valleys. While the Cardiff Jewish population was 13 families in 1852, after the influx of Jews fleeing from Russian pogroms in the 1880s the city's Jewish population rose to a peak of 5,500. A synagogue was founded in Merthyr Tydfil in 1875, and by the end of the century, most towns in the Valleys had small Jewish communities and trading stations. Generally, these communities appear to have been well tolerated, though there were some notable exceptions. In 1911, antisemitic sentiment came to a head in the Tredegar area, where working-class mobs attacked Jewish-owned businesses, causing thousands of pounds worth of damage. Early 20th-century Welsh Jewish society is featured in the 1999 film Solomon & Gaenor, which is set at the time of the Tredegar riots. Some of these topics were covered in the documentary The Kosher Comedian presented by Jewish-Welsh writer comedian Bennett Arron.
