Battle of Welfesholz The Battle of Welfesholz was fought on 11 February 1115 between the Imperial army of the Emperor Henry V and a rebellious Saxon force . Background . Henry V , scion of the Frankish Salian dynasty and uncontested King of the Romans since 1106 , had inherited both the Investiture Controversy and the Saxon conflict from his father Henry IV . In 1110 he moved to Italy and , after negotiation failed , captured Pope Paschal II and several cardinals to enforce his coronation as Holy Roman Emperor . Having returned from Rome he was immediately excommunicated by the papal legate in Germany Cuno of Praeneste and again by Archbishop Guy de Vienne , the later Pope Callixtus II , which encouraged the Imperial princes in their rising against the emperor — most of all the Saxon Duke Lothair of Supplinburg and Archbishop Adalbert of Mainz , Henry ' s long - time supporter who after his investiture had deserted him . Henry entrusted the Saxon affairs to his field marshal Count Henry of Mansfeld , a Saxon noble himself . However , though he had Adalbert imprisoned at Trifels Castle and forced Lothair to submit himself after a court hearing at the Imperial Palace of Goslar , the smouldering Saxon conflict broke out again in March 1113 over the succession in the Thuringian territories left by late Count Ulric II of Weimar and Orlamünde . In order to create an own power basis , Henry had made attempts to confiscate the county as a ceased fief but met obstinate resistance by Ulric ' s heir , the Count Palatine of the Rhine Siegfried , son of the Ascanian count Adalbert II of Ballenstedt . The insurgents gathered under the lead of the Osterland count Wiprecht of Groitzsch and the Thuringian count Louis the Springer , but were repulsed by Henry ' s troops under Mansfeld in a battle at Warnstedt near Thale . Wiprecht was captured and at first sentenced to death for high treason . Later he was reprieved , imprisoned at Trifels and divested of his possessions , which passed to the House of Mansfeld . The next year Duke Lothair had to attend Henry ' s wedding with Matilda of England in a hairshirt . Subdued though not deposed , he had continued intriguing against Henry , who saw himself confronted with the increasing opposition of the Imperial princes . In October 1114 the conflict again culmulated in violent fights , when Rhenish insurgents led by Archbishop Frederick I of Cologne had attacked the Imperial troops in October 1114 at Andernach . Battle . Meanwhile several nobles like the deposed Duke Henry of Lower Lorraine and the Saxon bishop Reinhard of Halberstadt , disgusted by Henry ' s haughty behaiviour , had joined the insurgents . According to the chronicles of Pegau Abbey , on 10 February 1115 the Imperial forces gathered at the " Kaiserpfalz " of Wallhausen and moved about towards Welfesholz ( today part of Gerbstedt in Saxony - Anhalt ) to meet the united Saxon troops led by Duke Lothair , with first skirmish occurring already on the same evening . The next day Henry ' s commander Hoyer of Mansfeld started an offensive whereby he was killed in a sword combat by the young robber knight Wiprecht II , son of the arrested Count Wiprecht of Groitzsch . The incident decided the battle : the tackling Saxon armies of Lothair were victorious , forcing Henry ' s troops to take flight . In his 12th century " Chronica Slavorum " the Saxon chronicler Helmold described the battle as " the largest encounter in our time " . Aftermath . The emperor ' s power to rule Saxony was denied , the Bishop of Halberstadt even refused a Christian burial of the killed enemies . In November , the Mainz citizens enforced the release of Archbishop Adalbert . However , Henry could still rely on the loyal support by his Hohenstaufen nephew Duke Frederick II of Swabia and his brother Conrad III . When the emperor again moved to Italy for the inheritance of Countess Matilda of Tuscany the next year , Duke Frederick was appointed regent , which laid the grounds for the rise of the Hohenstaufen dynasty . Contemporaneously , Lothair ' s position in Saxony was stabled . Count Wiprecht of Groitzsch was released in 1117 , he was appointed burgrave of the Magdeburg archbishop the next year . When Emperor Henry V vested him with the marches of Meissen and Lusatia in 1123 , Duke Lothair opposed his former ally , expelled him and granted the marches to Conrad of Wettin and the Ascanian count Albert the Bear . When the Salian dynasty became extinct with Henry ' s death in 1125 , Lothair , strongly backed by Archbishop Adalbert of Mainz , was elected King of the Romans against the Hohenstaufen duke Frederick of Swabia . The fate of Count Hoyer of Mansfeld was perpetuated in a poem by Theodor Körner ( 1791 – 1813 ) .