Siege of Gana

In the winter of 928, King Henry the Fowler of Germany organized a military expedition along his eastern frontier against various Slavic fortifications. His first objective was the Hevelli tribe's princely seat Brandenburg, located along the Havel river.[2] The Germans reduced Hevelli military power through a multitude of battles, before closing in on the Brandenburg fortress and capturing it by a storm.[3] Upon occupation of the fort, Henry proceeded to take over all of Hevelli territory.[4] The next German campaign target was the Glomacze fortress of Gana near the Jahna river.[5] On their way to Gana, Henry's army marched along the Plane valley to the Fläming hills, conquering more Slavic forts at Belzig, Mörz, Niemegk and Zahna.[6] Nearby, German forts were constructed in 929 at Strehla, controlling a ford over the Elbe, at Osterburg and at Dahlen, securing the area.[6]

Archaeological excavations have uncovered a fortress in the Jahna river valley near Stauchitz that may be identified with the Gana site.[7] The fort had walls 15 meters thick at their foundation and with a height of 6 meters.[7] It was enclosed by a 15-meter wide and 5-meter tall ditch.[7] The circuit of the walls was 700 meters long and the fort encompassed an area of 4 hectares, not including a possible outer fort.[7]

Filling in a 200-meter section of the ditch was necessary for Henry's men to storm the walls, a process that would have required the excavation of 15,000 tons of earth with at least 50,000 man-hours of work.[8] The earth then needed to be transported and unloaded on the ditch using wagons.[9] At least 750 carts and 30,000 wagon-loads of earth would have been needed, requiring another 60,000 man-hours of loading, transport and unloading.[10] With only 8 hours of daylight in the winter, it would have taken 1,000 men two weeks to accomplish the task.[10]

Once Gana was stormed at the end of the 20-day siege, Henry gave the order for his men to kill all the defenders and enslave the young boys and girls to his milites professional soldiers.[11] Given the ferocity of the German conquest, it is likely they had sustained heavy losses in the assault.[11] Bachrach estimates more than 1,000 Germans killed or wounded, based on a mathematical siege attack model for the Brandenburg fortification.[11]

After conquering Gana, Henry marched up the Elbe to accomplish his ultimate campaign aim, the siege of Prague and the subjugation of Duke Wenceslaus I's Duchy of Bohemia.[11] Along the way, he constructed a fortress at Meissen, as proven by dendrochronological dating of the wooden construction at Meissen, which establishes an early building stage for 929.[11] Meissen secured German control over the middle Elbe and was followed by the establishment of the Marca Geronis to maintain the German hold.[11][12] With the help of Duke Arnulf of Bavaria's troops, Henry invaded Bohemia with a total force of 12,000–15,000 professional soldiers and expeditionary militia levies and compelled the surrender of heavily-fortified Prague, concluding a highly successful campaign.[13][12]

• Bachrach, David (1 August 2013). "Henry I of Germany's 929 military campaign in archaeological perspective". Early Medieval Europe. Oxford: Wiley Blackwell. 21 (3): 307–337. doi:10.1111/emed.12020.CS1 maint: ref=harv (link)