A Celtic town stood on the hill now occupied by Basel’s Cathedral in the first century BC, but the city is traditionally dated to 44 BC, when the nearby Roman city of Augusta Raurica was also founded. By 374 AD, Basilia was a fort, and seat of a bishopric following the Alemans’ destruction of Augusta Raurica in the fifth century. In 917, the Huns swept through, sacking the town and destroying the Carolingian cathedral, but nonetheless by the thirteenth century, Basel had become a prominent town in the region. In 1225, Bishop Heinrich II of Thun built the first bridge across the Rhine – ancestor of today’s Mittlere Brücke – which coincided with the opening of a road over the Gotthard Pass into Italy, thus ensuring Basel’s continuing growth as a natural focus for trade. Plague ravaged the population in 1349, killing some 14,000, and just seven years later a major earthquake and subsequent fire razed much of the city. Shortly after, the two communities on either side of the Rhine – Grossbasel and Kleinbasel – united as a single city. For almost 20 years (1431–49), the ecumenical Council of Basel pushed the city into the European limelight as the church set about reforming itself; Pope Felix V was crowned in Basel during the council’s deliberations in 1440, and merchants, philosophers, emperors, princes and bishops flocked to the city, spurring the growth of papermaking, printing, and the development of ideas and trade in the region.

Responding to the impetus of the Renaissance, in 1460 Pope Pius II founded Basel’s university, Switzerland’s oldest and a major centre for humanism which was home to the philosopher Erasmus of Rotterdam throughout the 1520s and 1530s. During the sixteenth and seventeenth centuries, Protestant refugees from France, Flanders and Italy expanded Basel’s industries but, since the city remained under the thumb of both noble families and the church, most were not accepted as citizens. In 1831, disaffected residents in the rural communities around Basel launched a rebellion against the city oligarchs and after a brief civil war managed to secede, forming their own half-canton of Basel-Land (countryside), separate to this day from Basel-Stadt (city).

Throughout the nineteenth century, a massive growth in industry led to the construction of the gigantic port facilities on the Rhine at the turn of the twentieth century, which still handle a large proportion of Swiss import/export trade a century later. But Basel is best known these days as a centre of both banking and chemical industry: the companies which started out dyeing silk ribbons woven by Huguenot refugees centuries ago are now the world’s largest pharmaceutical companies, with their headquarters and laboratory facilities still in Basel. The Bank for International Settlements (BIS) – a kind of supranational controlling body used by governments and national banks – was founded in Basel in 1929.