Analysis of information sources in references of the Wikipedia article "Heinrich IV của Thánh chế La Mã" in Vietnamese language version.
Godfrey was almost certainly present in support of Henry IV at the battle of Elster in 1080 (sic 1085), when the forces of the anti-king Rudolf triumphed on the field only to see their victory nullified because Rudolf was killed
One of two brief accounts of the battle of Volta reports it occurred on the same day as the battle of Elster (15 October 1080) in which Rudolf was fatally wounded.
