▁river ▁O der . ▁Three ▁of ▁the ▁ 9 th ▁Army ' s ▁form ations ▁were ▁task ed ▁with ▁def ending ▁the ▁Se el ow ▁He ights , ▁which ▁was ▁the ▁last ▁def ens ible ▁region ▁before ▁Berlin . ▁To ▁the ▁north ▁was ▁the ▁CI ▁Army ▁Corps , ▁in ▁the ▁centre ▁General ▁Hel m uth ▁We id ling ' s ▁L VI ▁Pan zer ▁Corps , ▁and ▁to ▁south ▁of ▁the ▁He ights ▁was ▁the ▁XI ▁SS ▁Pan zer ▁Corps . ▁In ▁addition ▁south ▁of ▁Frankfurt ▁( which ▁was ▁def ended ▁by ▁the ▁Frankfurt ▁G arrison ) ▁was ▁the ▁V ▁SS ▁Mountain ▁Corps . ▁In ▁total ▁the ▁ 9 th ▁Army ▁was ▁reduced ▁to ▁ 1 0 0 , 0 0 0 ▁men ▁and ▁ 8 0 0 ▁t anks ▁and ▁assault ▁guns ▁against ▁which ▁the ▁S ovi ets ▁had ▁over ▁ 1 , 0 0 0 , 0 0 0 ▁men ▁and ▁ 1 0 , 0 0 0 ▁t anks ▁and ▁assault ▁guns . ▁ ▁The ▁Battle ▁of ▁the ▁Se el ow ▁He ights ▁started ▁on ▁ 1 6 ▁April ▁ 1 9 4 5 ▁when ▁Marsh al ▁Georg y ▁Zh uk ov ' s ▁ 1 st ▁Bel or uss ian ▁Front ▁attacked ▁across ▁the ▁O der . ▁The ▁ 9 th ▁Army ▁held ▁the ▁line ▁for ▁about ▁ 3 ▁days . ▁After ▁heavy ▁fighting ▁We id ling ' s ▁L VI ▁Pan zer ▁Corps ▁was ▁driven ▁back ▁towards ▁Berlin . ▁Most ▁of ▁the ▁CI ▁Army ▁Corps ▁divisions , ▁now