▁of ▁the ▁phil os opher ▁Z eng zi . ▁He ▁served ▁in ▁the ▁X i ang ▁Army , ▁a ▁standing ▁military ▁force ▁organ ised ▁by ▁his ▁brother ▁to ▁counter ▁the ▁Ta ip ing ▁reb els , ▁and ▁was ▁nick named ▁" N inth ▁Marsh al " ▁( 九 <0xE5> <0xB8> <0xA5> ). ▁He ▁was ▁known ▁for ▁his ▁expert ise ▁in ▁sie ge ▁war fare , ▁particularly ▁the ▁use ▁of ▁tren ches , ▁hence ▁he ▁was ▁also ▁nick named ▁" Z eng ▁the ▁Iron ▁Container " ▁( <0xE6> <0x9B> <0xBE> <0xE9> <0x90> <0xB5> <0xE6> <0xA1> <0xB6> ). ▁During ▁the ▁con quest ▁of ▁T ian j ing ▁( N an j ing ), ▁the ▁capital ▁of ▁the ▁Ta ip ing ▁Heaven ly ▁Kingdom , ▁Z eng ▁was ▁not orious ▁for ▁cond oning ▁mass ac res ▁of ▁the ▁city ▁popul ace , ▁which ▁resulted ▁in ▁him ▁being ▁called ▁" Z eng ▁the ▁But cher " ▁( <0xE6> <0x9B> <0xBE> <0xE5> <0xB1> <0xA0> <0xE6> <0x88> <0xB6> ). ▁ ▁Life ▁Z eng ▁was ▁born ▁in ▁X i ang xi ang , ▁Ch ang sha ▁Pref ect ure , ▁Hun an ▁Province . ▁Z eng zi ▁was ▁his ▁ancest or . ▁He ▁sat ▁for ▁the ▁imperial ▁exam ination ▁several ▁times ▁but ▁failed ▁to ▁make ▁the ▁cut . ▁During ▁the ▁Ta ip ing ▁Reb ell ion , ▁Z eng ▁assist ed ▁his ▁brother ▁Z eng ▁Gu of an ▁in ▁raising ▁and ▁organ ising ▁local ▁milit ias ▁from ▁Hun an ▁to ▁form ▁the ▁X i ang ▁Army ▁to ▁fight ▁the ▁reb