Danube River

The Danube was the northeastern frontier of the Roman empire for four centuries, and the religious consequence of that is a dense band of military cult sites running from the Black Forest to the Black Sea.

The legions stationed along it brought their own gods and adopted others. Mithras is the most conspicuous: the cult's underground meeting rooms, with their standard relief of the god killing a bull, are found in unusual concentration in the Danube provinces, and the membership was heavily military and administrative. Roger Beck's study of the cult's structure argues that its imagery encodes an account of the soul's passage through the heavens, taught in stages to initiates who were sworn to secrecy, which is why the archaeology is abundant and the doctrine has to be reconstructed.

Local deities were absorbed alongside. Danuvius, the river itself, received dedications; the Danubian Rider reliefs, a distinctive regional type showing one or two horsemen and a goddess, are found nowhere else and remain poorly understood.

The frontier also determined where Christianity took hold early. Garrison towns became bishoprics, and the martyr accounts of the Danube provinces are among the earliest in central Europe. When the empire withdrew, the river remained a line: it later marked much of the boundary between Latin and Greek Christianity, and then between Christendom and the Ottoman empire.

The Danube's later religious history is a history of boundaries drawn along it and armies moving up and down it.

Ottoman expansion into Europe followed the river valley, and the two sieges of Vienna, in 1529 and 1683, were fought at the point where it enters the German lands. The relief of the second was preached as a Christian undertaking and is still commemorated as such, and the Habsburg reconquest of Hungary that followed brought a Catholic restoration to territory that had been substantially Protestant, which is why the religious map of the middle Danube looks the way it does.

Downstream the river separated Catholic and Orthodox populations for centuries, and the modern states along it inherited that division: Austria and Hungary Catholic, Serbia, Bulgaria and Romania Orthodox, with Muslim communities remaining from the Ottoman period throughout.

The twentieth century added something else. In the winter of 1944 and 1945, members of the Arrow Cross militia took Jews from the Budapest ghetto to the embankment, ordered them to remove their shoes, shot them and let the river carry the bodies away. A memorial installed in 2005 consists of sixty pairs of iron shoes on the stone edge, in the styles of the period, arranged as though just stepped out of. It is among the least rhetorical Holocaust memorials in Europe and one of the most visited.