Henry II started his Italian campaign in the fall of 1013, defeated the allies of the Crescentians and had pope Benedict VIII crown him Holy Roman Emperor in Rome on 14 February 1014. Bohemian duke Oldrich (Udalrich) meanwhile captured Bolesław I's son, Mieszko, and turned him over to Henry II, who however released him. In July 1015, Henry II with his Lutician allies renewed the war against Bolesław I on the basis of the latter's failure to support him in Italy. The campaign started in Magdeburg, from where Henry II's army crossed through Lusatia to Krosno, where two other armies commanded by Bernard II of Saxony and Olrich (Udalrich) of Bohemia were supposed to join him. The plan failed however, as Bolesław's maneuvers prevented the two armies from joining up. During the fighting Margrave Gero, as well as two hundred other German knights were killed by Polish bowmen and Bolesław allowed the Bishop of Meissen, Eido, to recover the bodies for burial. As a result of these setbacks Henry II withdrew. Subsequent negotiations with Bolesław I failed. In 1017, Henry II marched an army from Leitzkau to Głogów (Glogau), where Bolesław I awaited him, but chose not to besiege the city as it was too strongly fortified. Instead Henry besieged nearby Niemcza (Nemzi, Nimptsch), however, Polish reinforcements managed to enter the city on two occasions and the siege was without success. The contemporary German chronicler Thietmar of Merseburg, generally ill-disposed towards Poles, on this occasion commented on the bravery and skill of the defenders, noting that they neither cheered when they were successful, nor lamented when they suffered a setback. The inhabitants of the city also erected a cross on the wall which faced the pagan Lutician allies of the emperor. Eventually, due to an illness of part of his army Henry aborted the siege and withdrew, taking the route to Bohemia because the way back into Germany was blocked by Boleslaw's main forces, stationed at Wrocław. During these campaigns, Henry II was confronted with the opposition of part of the Saxon nobility, including the House of Billung, who maintained good relations and were in part relatives of Bolesław I. In 1017, Henry II therefore addressed Bolesław I as "public enemy" ("hostis publicus") and forbade further contacts with him.