Meanwhile, "Isern Hinnerk" expanded his brigandages, to robb the means to accomplish his castle. Grand excommunicated him, but "Isern Hinnerk" even spread his robberies to neighboured Brunswick and Lunenburg-Celle and the Prince-Bishopric of Verden. This brought about a coalition of Grand with Duke Otto II "the Strict" of Brunswick and Lunenburg-Celle and Prince-Bishop Frederick I inflicting a feud on "Isern Hinnerk", which would put an end to his robberies. They destroyed his castle "Dannensee", beleaguered the castle in Horneburg, where he found refuge with relatives. After a second flight Hinnerk was enjailed in Vörde in 1311. The population appreciated Grand's success, because after years of insecurity he re-established order in the Prince-Archbishopric.