t ▁L ễ . ▁ ▁Like ▁his ▁prede cess or ▁D ụ ▁T ô ng , ▁N h ậ t ▁L ễ ▁neglect ed ▁his ▁administrative ▁duties ▁and ▁concentr ated ▁only ▁in ▁drink ing , ▁theatre ▁and ▁wand ering . ▁He ▁even ▁wanted ▁to ▁change ▁his ▁family ▁name ▁back ▁to ▁D ư ơ ng . ▁Such ▁activities ▁disappoint ed ▁everyone ▁in ▁the ▁royal ▁court . ▁This ▁once ▁prompt ed ▁the ▁Prime ▁Minister ▁Tr ầ n ▁N gu y ên ▁Tr ác ▁and ▁his ▁son ▁Tr ầ n ▁N gu y ên ▁Ti ế t ▁to ▁plot ▁the ▁assass ination ▁of ▁N h ậ t ▁L ễ , ▁but ▁their ▁consp i racy ▁was ▁discovered ▁by ▁the ▁Emperor ▁and ▁they ▁were ▁killed ▁afterwards . ▁In ▁the ▁t enth ▁month ▁of ▁ 1 3 7 0 , ▁the ▁Emperor ' s ▁father - in - law , ▁Tr ầ n ▁Ph ủ , ▁after ▁receiving ▁advice ▁from ▁several ▁mand ar ins ▁and ▁members ▁of ▁the ▁royal ▁family , ▁decided ▁to ▁raise ▁an ▁army ▁for ▁the ▁purpose ▁of ▁over throw ing ▁N h ậ t ▁L ễ . ▁After ▁one ▁month , ▁his ▁plan ▁succeeded ▁and ▁Tr ầ n ▁Ph ủ ▁became ▁the ▁new ▁em peror ▁of ▁ Đ ạ i ▁Vi ệ t , ▁r uling ▁as ▁Tr ầ n ▁N gh ệ ▁T ô ng , ▁while ▁N h ậ t ▁L ễ ▁was ▁down grad ed ▁to ▁Duke ▁of ▁H ô n ▁ Đ ứ c ▁( H ô n ▁ Đ ứ