
Some 50 miles east of Berlin lies the Polish town of Cedynia. Since the 1960s, on every 24th of June it is the scene of a festival commemorating the Battle of Cedynia, which took place there in 972 CE. Reenactment aficionados replay the battle in mediaeval costumes, there are open air concerts, and blacksmiths and potters display their trades.
The battle itself, then, took place over 1000 years ago, between the forces of German count Odo I and Polish warlord Mieszko. Odo was as a vassal of German emperor Otto I. His attack on Mieszko’s lands was against the wishes of the Kaiser, as Mieszko himself, the first documented ruler of Greater Poland, also paid tribute to the empire. Odo was unable to beat his Polish opponent and the battle ended in a truce. A year later, Otto, the old emperor, would lay down a judgement settling the matter, but the conflict was only fully resolved when Mieszko married a German noblewoman some seven years later.
But why does this ancient and forgotten battle (at least until after World War Two) get so much attention now? The reason is Cedynia’s situation on the Oder river, part of the famous Oder-Neisse line.

When Stalin demanded that Poland should be shifted westwards at the end of World War Two, this happened at the expense of German territories like the easternmost part of the Prussian province of Brandenburg. The town of Cedynia (which was called Zehden until 1945) became Poland’s most westerly city. All German-speaking citizens were deported from the area, and the town became the new home of refugees that Stalin had chased from the east of pre-war Poland.

The selection of the Oder-Neisse line as the new Polish-German frontier had a long diplomatic aftermath. The GDR accepted the new border as soon as 1950, but the Federal Republic (or West Germany) didn’t formally agree until 1970. The German reunification treaty of 1990 again acknowledged the border specifically, hoping to assuage Polish fears of German expansionism. So, in the 1950s and 60s, it is understandable that Poland’s communist regime was not quite certain of the status quo of its new western frontier. Politicians knew perfectly well that the area had been German for a long time, and the state did its best to justify its claims on the territory. Clearly they weren’t fully convinced that the atrocities inflicted upon Poland by the Nazis during the war were justification enough for some compensatory annexation.

So, Polish politicians started looking for any historical sources that could justify their