后趙(zhao)建武四(si)年(338年)五月,后趙(zhao)皇帝石虎(hu)以(yi)燕軍違約獨攻段部鮮(xian)卑,得勝。又以(yi)劫掠而(er)歸為由,發兵(bing)數十萬北(bei)伐,圍困大(da)(da)棘(ji)城(今遼寧(ning)義(yi)縣)。燕趙(zhao)兩(liang)軍相(xiang)持(chi)十余日(ri),趙(zhao)軍不能克,遂(sui)后退(tui)。慕容(rong)皝(huang)派慕容(rong)恪率(lv)2000騎兵(bing)于(yu)清晨出城追(zhui)殺。石虎(hu)見(jian)城內師出,大(da)(da)驚,棄甲潰逃。慕容(rong)恪乘勝追(zhui)擊,大(da)(da)敗后趙(zhao)軍,斬獲(huo)三萬余級。
后(hou)趙建武四(si)年(nian)(338年(nian))十二月,段部鮮卑首領段遼遣使(shi)向后(hou)趙請(qing)降,中途反悔(hui),又遣使(shi)請(qing)降于前(qian)(qian)燕,并與前(qian)(qian)燕合謀設伏,欲(yu)消(xiao)滅趙軍。時后(hou)趙皇帝石虎已派征東(dong)將軍麻(ma)秋、司(si)馬陽(yang)裕等(deng)率兵3萬前(qian)(qian)去受降。前(qian)(qian)燕王(wang)慕容(rong)(rong)皝自統大(da)軍前(qian)(qian)往迎段遼,派慕容(rong)(rong)恪帶精騎7000埋(mai)伏于密云山。慕容(rong)(rong)恪大(da)敗麻(ma)秋于三藏口(今河北(bei)承(cheng)德),趙軍死亡大(da)半,麻(ma)秋步(bu)行逃脫,司(si)馬陽(yang)裕被俘(fu)。
咸(xian)康七年(nian)(341)年(nian)十月,燕(yan)王(wang)慕(mu)(mu)容皝以慕(mu)(mu)容恪(ke)為渡遼(liao)將軍(jun),鎮(zhen)守(shou)(shou)平(ping)郭。前燕(yan)自從慕(mu)(mu)容翰逃亡,慕(mu)(mu)容仁被殺后,無人(ren)能鎮(zhen)守(shou)(shou)遼(liao)東。慕(mu)(mu)容恪(ke)行至平(ping)郭,撫(fu)舊懷新,屢(lv)破高句麗兵,高句麗畏之,不(bu)敢再(zai)入(ru)燕(yan)境。
建(jian)元二(er)年(nian)(344年(nian))二(er)月(yue),慕(mu)容皝親自帶兵攻(gong)宇(yu)文逸(yi)豆歸,以建(jian)威(wei)將軍慕(mu)容翰(于咸康(kang)六(liu)年(nian)回到(dao)燕國)為前(qian)鋒將軍,劉佩為副將;命慕(mu)容恪與慕(mu)容軍、慕(mu)容霸及折(zhe)沖將軍慕(mu)輿根等率兵分三(san)路(lu)并進(jin)。最終大(da)破宇(yu)文軍,燕軍乘勝追(zhui)擊,攻(gong)克宇(yu)文氏都城(cheng)紫蒙川(今(jin)遼寧朝陽西北(bei))。宇(yu)文逸(yi)豆歸敗逃,死于漠北(bei),宇(yu)文氏從此散亡。
永(yong)和(he)元年(345年)十月(yue),慕(mu)(mu)容(rong)皝令慕(mu)(mu)容(rong)恪攻打(da)高句麗(li)。慕(mu)(mu)容(rong)恪攻拔南蘇(su)(今遼寧(ning)撫順市(shi)東蘇(su)子河與(yu)渾河合(he)流處(chu)),派兵留守。永(yong)和(he)二年(346年)正月(yue),慕(mu)(mu)容(rong)皝派慕(mu)(mu)容(rong)恪與(yu)世子慕(mu)(mu)容(rong)儁、慕(mu)(mu)容(rong)軍、慕(mu)(mu)輿根及1.7萬(wan)騎(qi)兵襲擊扶(fu)余國。慕(mu)(mu)容(rong)儁坐(zuo)鎮中(zhong)軍指揮,而慕(mu)(mu)容(rong)恪則統(tong)帥諸軍冒矢石進(jin)擊,攻克扶(fu)余,俘扶(fu)余國王玄及部落5萬(wan)余口(kou)而還。
永和六(liu)年(nian)(350年(nian)),后趙(zhao)大(da)(da)將軍(jun)冉(ran)閔占(zhan)據鄴(ye)城,滅亡后趙(zhao)。自立為帝,國號大(da)(da)魏,史稱冉(ran)魏。
永和七(qi)年(351年)八月,慕容(rong)儁遣慕容(rong)恪(ke)(ke)攻破中山(今河(he)北定州)。隨(sui)著(zhu)慕容(rong)恪(ke)(ke)攻占中山后,冉閔攻取了襄國(今河(he)北邢臺),欲圖(tu)幽州。前燕占領幽州后,也(ye)想繼續南進,圖(tu)據中原,一場(chang)大戰不可避免。
永和(he)八年(352年)四月,冉(ran)(ran)閔(min)(min)(min)(min)將(jiang)(jiang)與前燕(yan)開(kai)戰(zhan)(zhan)。大將(jiang)(jiang)軍(jun)(jun)董閏、車騎(qi)將(jiang)(jiang)軍(jun)(jun)張溫苦(ku)諫冉(ran)(ran)閔(min)(min)(min)(min),不(bu)可同(tong)前燕(yan)開(kai)戰(zhan)(zhan)。冉(ran)(ran)閔(min)(min)(min)(min)不(bu)納,移軍(jun)(jun)于安(an)喜(今河北定州)。慕容(rong)恪(ke)隨即引(yin)兵而(er)至(zhi)。魏燕(yan)兩軍(jun)(jun)交戰(zhan)(zhan)十次,燕(yan)兵皆敗(bai)(bai)。冉(ran)(ran)閔(min)(min)(min)(min)素有勇(yong)名,所(suo)(suo)部(bu)(bu)將(jiang)(jiang)士精銳,燕(yan)軍(jun)(jun)畏懼(ju)。慕容(rong)恪(ke)陣前激(ji)勵將(jiang)(jiang)士,指出(chu)冉(ran)(ran)閔(min)(min)(min)(min)有勇(yong)無謀,其(qi)軍(jun)(jun)饑疲難用,定可擊(ji)破。冉(ran)(ran)閔(min)(min)(min)(min)所(suo)(suo)部(bu)(bu)多步(bu)卒,欲引(yin)燕(yan)騎(qi)兵至(zhi)叢林作(zuo)戰(zhan)(zhan)。慕容(rong)恪(ke)采納參(can)軍(jun)(jun)高開(kai)之策,急(ji)派輕騎(qi)截擊(ji)之,然后(hou)佯敗(bai)(bai)誘敵至(zhi)平地(di),并將(jiang)(jiang)燕(yan)軍(jun)(jun)切分為三部(bu)(bu)。慕容(rong)恪(ke)自率中(zhong)軍(jun)(jun),選善射者五千人(ren),以鐵鎖連戰(zhan)(zhan)馬結方(fang)陣而(er)前,另兩部(bu)(bu)各置(zhi)一側配合(he)主力(li)進(jin)擊(ji)。冉(ran)(ran)閔(min)(min)(min)(min)恃勇(yong)輕敵,果然中(zhong)計,直突燕(yan)軍(jun)(jun)中(zhong)部(bu)(bu)鐵馬方(fang)陣。燕(yan)軍(jun)(jun)側翼(yi)部(bu)(bu)隊(dui)即從兩面夾擊(ji),大敗(bai)(bai)冉(ran)(ran)閔(min)(min)(min)(min)軍(jun)(jun)隊(dui),斬七千余人(ren)。冉(ran)(ran)閔(min)(min)(min)(min)突圍東走二十余里,坐騎(qi)忽死,被(bei)燕(yan)軍(jun)(jun)所(suo)(suo)俘,冉(ran)(ran)魏滅(mie)亡。
元(yuan)璽元(yuan)年(nian)(nian)(352年(nian)(nian)),冉(ran)閔被慕容(rong)恪軍俘虜后,其子冉(ran)操(cao)投奔鎮守魯(lu)(lu)口(kou)(kou)(今河北饒陽)的(de)大將(jiang)(jiang)王(wang)(wang)(wang)午(wu)。七月,王(wang)(wang)(wang)午(wu)自(zi)稱安國王(wang)(wang)(wang),對抗(kang)前燕(yan)。八月,慕容(rong)儁遣慕容(rong)恪、太尉封奕、尚書令陽騖攻(gong)打(da)魯(lu)(lu)口(kou)(kou)。王(wang)(wang)(wang)午(wu)憑借城(cheng)池(chi)之險(xian)進行(xing)抵抗(kang),并把冉(ran)操(cao)送于燕(yan)軍。慕容(rong)恪料(liao)魯(lu)(lu)口(kou)(kou)城(cheng)池(chi)堅固,暫難(nan)攻(gong)克,遂將(jiang)(jiang)城(cheng)外的(de)莊稼盡(jin)數(shu)收割,撤(che)回中山(今河北定州市)。十月,慕容(rong)恪屯安平,積糧,修筑攻(gong)城(cheng)器具,準備攻(gong)討王(wang)(wang)(wang)午(wu)。時中山蘇(su)林起兵(bing)于無極,自(zi)稱天子,慕容(rong)恪率軍先攻(gong)討蘇(su)林。十月,慕容(rong)儁派廣威將(jiang)(jiang)軍慕輿(yu)根幫助(zhu)慕容(rong)恪,斬(zhan)蘇(su)林。不(bu)久,王(wang)(wang)(wang)午(wu)為(wei)其將(jiang)(jiang)秦興(xing)殺(sha)死,呂護又(you)殺(sha)秦興(xing),繼(ji)承(cheng)安國王(wang)(wang)(wang)。
元(yuan)璽三年(354年)二月(yue),慕容恪再次發兵圍魯口,次月(yue)克之(zhi)。呂護逃往野王(wang)(今河南沁(qin)陽)。四月(yue),慕容儁以慕容恪為大司(si)馬、侍(shi)中、大都督(du)、錄尚書事(shi),封太原王(wang)。
建熙二(er)年(361年)二(er)月,寧(ning)南將軍(jun)(jun)呂(lv)護(hu),鎮(zhen)守(shou)野王(今河(he)南沁陽),暗(an)中(zhong)投靠(kao)東(dong)晉,東(dong)晉以呂(lv)護(hu)為前將軍(jun)(jun)、冀(ji)州(zhou)刺史。呂(lv)護(hu)欲引東(dong)晉軍(jun)(jun)偷襲燕都鄴城(cheng)(今河(he)北臨漳(zhang)),未(wei)及(ji)行(xing)動(dong),事情敗露。
三月(yue),燕(yan)王(wang)(wang)遣慕(mu)容恪(ke)統(tong)軍(jun)(jun)前(qian)往野王(wang)(wang)平叛(pan)。慕(mu)容恪(ke)率軍(jun)(jun)5萬,冠軍(jun)(jun)將軍(jun)(jun)皇甫真領兵(bing)1萬,進至野王(wang)(wang)城(cheng)外,呂護閉(bi)城(cheng)固守。慕(mu)容恪(ke)遂于野王(wang)(wang)城(cheng)外修筑深溝(gou)高壘,切斷守軍(jun)(jun)外援,以待(dai)機擊之。
七月,呂(lv)(lv)(lv)護軍(jun)被(bei)圍(wei)數月,外無救(jiu)兵,內無糧(liang)草(cao)。呂(lv)(lv)(lv)護被(bei)迫令部(bu)將張(zhang)興率(lv)領7000人(ren)馬出城迎戰,張(zhang)興被(bei)傅顏斬(zhan)殺。當夜,呂(lv)(lv)(lv)護以黃甫真營陣(zhen)為突(tu)圍(wei)口,率(lv)城中銳(rui)卒試圖突(tu)圍(wei)。皇(huang)甫真事先已做好(hao)防備,慕容恪(ke)領兵從(cong)側翼出擊,呂(lv)(lv)(lv)護所部(bu)死傷慘重,呂(lv)(lv)(lv)護單騎逃往滎(ying)陽(yang)(今河南滎(ying)陽(yang)),燕軍(jun)攻克野(ye)王(wang),結(jie)束(shu)野(ye)王(wang)之戰。
永和六(liu)年(350年)前后(hou),原(yuan)段氏鮮卑首領(ling)段蘭之子(zi)段龕(kan)乘著后(hou)趙內(nei)亂(luan)、冉魏(wei)新立之機,統帥部眾南遷(qian)陳留(今河南開封(feng))。七月,東遷(qian)廣固(今山東青州(zhou)),自稱齊王,向東晉(jin)稱臣,受(shou)封(feng)為鎮(zhen)北將軍。
元璽四(si)年(355年),前燕(yan)攻(gong)(gong)滅石(shi)氏、冉魏的勢力(li),開拓疆(jiang)域,成(cheng)為(wei)(wei)地跨幽、冀、并、平四(si)州的政(zheng)權(quan),掙脫東晉(jin),慕(mu)容儁(jun)自稱為(wei)(wei)帝。段(duan)龕以為(wei)(wei)與慕(mu)容儁(jun)同出鮮卑,致書(shu)慕(mu)容儁(jun)稱帝之(zhi)非;加之(zhi)段(duan)部所據(ju)廣固,勢力(li)漸強,已威脅前燕(yan)的統(tong)治,慕(mu)容儁(jun)遂(sui)決意發兵攻(gong)(gong)廣固。十(shi)一月,慕(mu)容儁(jun)以慕(mu)容恪為(wei)(wei)大(da)都督(du)、撫軍(jun)將軍(jun),尚書(shu)令(ling)陽(yang)騖為(wei)(wei)副將,率軍(jun)進(jin)攻(gong)(gong)廣固。十(shi)二月,燕(yan)軍(jun)至黃河北岸,慕(mu)容恪先(xian)以輕舟渡河,試探虛實。
元(yuan)璽五年(nian)(356年(nian))正月,慕(mu)(mu)容恪(ke)率(lv)軍(jun)(jun)渡過黃河,距廣固(gu)百余(yu)里。段龕(kan)率(lv)軍(jun)(jun)3萬人迎戰,慕(mu)(mu)容恪(ke)于淄水戰敗段龕(kan),數(shu)千(qian)名士卒投降(jiang)燕(yan)軍(jun)(jun)。段龕(kan)逃回廣固(gu),閉城固(gu)守。慕(mu)(mu)容恪(ke)率(lv)燕(yan)軍(jun)(jun)在廣固(gu)城外(wai)修高墻挖深塹(qian)圍(wei)困之(zhi)。并招(zhao)撫廣固(gu)四周(zhou)諸城,段龕(kan)所署(shu)徐州刺(ci)史王騰等于二月投降(jiang)慕(mu)(mu)容恪(ke)。
慕容恪(ke)圍廣固(gu)七個(ge)月后,段龕(kan)難以(yi)支撐,遂派人向(xiang)東(dong)(dong)晉求援。八月,東(dong)(dong)晉派徐(xu)州(zhou)刺史荀(xun)羨前往解圍。荀(xun)羨行(xing)至瑯琊,畏懼燕軍不進(jin)。恰逢(feng)王騰帶軍攻打鄄(juan)城(今(jin)山(shan)東(dong)(dong)鄄(juan)城),荀(xun)羨遂進(jin)攻陽都(今(jin)山(shan)東(dong)(dong)沂(yi)南),斬王騰。不久,廣固(gu)城內路人相食(shi),無以(yi)為守(shou)(shou)(shou)。段龕(kan)悉眾(zhong)出戰,被慕容恪(ke)在(zai)圍里擊敗,單騎(qi)逃回城中。十一月,段龕(kan)計(ji)窮,只得出降。慕容恪(ke)安撫百姓(xing),平定齊地(di),遷鮮(xian)卑、胡、羯三千(qian)余戶至薊。留慕容塵鎮廣固(gu),以(yi)尚(shang)書左丞鞠殷為東(dong)(dong)萊太守(shou)(shou)(shou),章武太守(shou)(shou)(shou)鮮(xian)于亮為齊郡(jun)太守(shou)(shou)(shou),率(lv)軍而(er)還。
廣固城(cheng)之(zhi)戰后,東(dong)晉泰(tai)山(shan)(shan)太守諸葛攸(you)進攻東(dong)郡(今(jin)河(he)(he)南(nan)濮陽(yang))。慕(mu)(mu)容恪(ke)領統陽(yang)騖、慕(mu)(mu)容臧率兵(bing)進擊,大敗晉軍,諸葛攸(you)退回太山(shan)(shan)(今(jin)山(shan)(shan)東(dong)泰(tai)安)。慕(mu)(mu)容恪(ke)乘勝渡過黃河(he)(he),占領河(he)(he)南(nan)部(bu)分土地,并設守宰。此后,前燕(yan)轄境迅速延至黃河(he)(he)以南(nan),對(dui)東(dong)晉構成了威脅。
光壽三年(359年),慕(mu)(mu)(mu)容(rong)儁患(huan)病(bing),對慕(mu)(mu)(mu)容(rong)恪說:朕病(bing)得這么(me)虛弱,恐怕(pa)是(shi)好(hao)不(bu)了。壽命長短,都沒有什(shen)么(me)可怨(yuan)恨的(de)了!不(bu)過,現在東晉和前秦未(wei)除,太子慕(mu)(mu)(mu)容(rong)暐年幼。朕擔心他(ta)應付不(bu)來,想效法宋宣公,將(jiang)皇位交(jiao)給你。慕(mu)(mu)(mu)容(rong)恪堅決拒絕,更(geng)說:“陛下若果(guo)認為(wei)臣能(neng)夠承擔安定(ding)天下的(de)重(zhong)責,難道就(jiu)沒能(neng)好(hao)好(hao)輔助少主!”慕(mu)(mu)(mu)容(rong)儁聽(ting)后十分高興。
光(guang)壽(shou)四年(nian)(360年(nian))正月(yue),慕(mu)容(rong)儁在鄴城大閱郡(jun)國之兵,欲派大軍進攻秦(qin)、晉,但(dan)病情轉危,遂召慕(mu)容(rong)恪、慕(mu)容(rong)鶩、慕(mu)容(rong)評及慕(mu)輿(yu)根(gen)等受(shou)遺(yi)詔(zhao)輔政,旋即病卒,時年(nian)四十二歲,葬于龍陵,謚號景昭皇(huang)帝(di),廟號烈祖。皇(huang)太子(zi)慕(mu)容(rong)暐即位(wei),年(nian)僅十一歲。二月(yue),尊皇(huang)后可足渾氏(shi)為皇(huang)太后,以(yi)慕(mu)容(rong)恪太宰、錄尚書(shu)事(shi),行(xing)周(zhou)公事(shi),總攝朝政。
不(bu)(bu)過,當時作為(wei)(wei)太(tai)(tai)師輔政的慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen)自恃戰功顯赫,高(gao)傲自大,看不(bu)(bu)起(qi)慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)。慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen)為(wei)(wei)挑(tiao)起(qi)事端以(yi)作亂,先以(yi)可足渾太(tai)(tai)后(hou)干政來挑(tiao)撥(bo)慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke),謊(huang)稱(cheng)支(zhi)持慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)奪位。但慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)不(bu)(bu)受。吳(wu)王慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)垂以(yi)及皇(huang)甫(fu)真(zhen)及后(hou)都勸他誅殺(sha)(sha)慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen),但慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)以(yi)皇(huang)帝新死,國家安穩為(wei)(wei)首要,決定忍耐(nai)。慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen)挑(tiao)撥(bo)慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)不(bu)(bu)成,于是試圖離間慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)暐(wei)母(mu)子(zi),想要太(tai)(tai)后(hou)誅殺(sha)(sha)慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)等。新帝慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)暐(wei)支(zhi)持慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke),勸止了母(mu)親。與此同時,前燕已經在(zai)滅冉魏后(hou)遷都鄴城,以(yi)舊(jiu)都龍城(今遼寧朝陽市)為(wei)(wei)留京。慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen)思戀遼東祖地,力勸太(tai)(tai)后(hou)和慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)暐(wei)建(jian)議還都龍城,變相(xiang)放棄(qi)中原地區。慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)恪(ke)(ke)(ke)(ke)(ke)知道后(hou),聯合慕(mu)(mu)(mu)(mu)(mu)容(rong)(rong)評密奏慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen)罪狀(zhuang),派衛將軍傅顏誅殺(sha)(sha)了慕(mu)(mu)(mu)(mu)(mu)輿(yu)根(gen)及其黨(dang)羽。
面對(dui)皇帝(di)新死,就發(fa)生(sheng)誅殺輔政(zheng)(zheng)重臣的(de)(de)事件,國內憂(you)慮(lv)情(qing)緒很高。慕(mu)(mu)容(rong)(rong)恪舉止如(ru)常,出入都只有一人跟從,不(bu)肯加添守衛。然后(hou)大赦天下,并停(ting)發(fa)慕(mu)(mu)容(rong)(rong)儁生(sheng)前所集(ji)各路兵(bing)員,受任理政(zheng)(zheng),兢兢嚴謹(jin),與司徒慕(mu)(mu)容(rong)(rong)評共同協作,虛(xu)心待士,諮諏善道,量(liang)才(cai)授任,燕政(zheng)(zheng)為之一新。于是,境(jing)內局(ju)勢漸穩,人心稍為安定。同時,原先征集(ji)在鄴城的(de)(de)各郡軍(jun)人都因為國家(jia)內部紛亂而(er)經常逃跑,而(er)鄴城向南(nan)(nan)方(fang)領地的(de)(de)道路通(tong)訊(xun)不(bu)暢通(tong)。慕(mu)(mu)容(rong)(rong)恪命(ming)令(ling)慕(mu)(mu)容(rong)(rong)垂南(nan)(nan)鎮蠡臺(tai)(今河(he)南(nan)(nan)商丘(qiu)),傅顏率軍(jun)南(nan)(nan)巡淮河(he),終令(ling)國家(jia)安穩下來。
建熙六年(365年)二月(yue),慕(mu)容(rong)恪與吳王慕(mu)容(rong)垂共攻洛陽。三(san)月(yue),克之(zhi),俘(fu)虜揚武將軍沈(shen)勁(jing)。慕(mu)容(rong)恪惜之(zhi)為(wei)奇士欲赦免,慕(mu)容(rong)虔上書(shu)說(shuo):沈(shen)勁(jing)雖為(wei)奇士,卻終(zhong)不可(ke)為(wei)己所(suo)用(yong),留之(zhi)必患。遂斬(zhan)殺沈(shen)勁(jing)。
慕容恪奪(duo)取(qu)洛陽后,隨即略地至崤山、澠池(chi),關中大震,前秦天王苻堅親自到陜(shan)城(cheng)進(jin)行防(fang)備。不久,慕容恪率軍撤回鄴城(cheng)。
當時吳(wu)王慕容(rong)垂才能出眾(zhong),慕容(rong)恪對其非常倚重,曾多次向燕主(zhu)進行推(tui)薦。
建熙七(qi)年(nian)(366年(nian)),慕(mu)容(rong)恪(ke)病重,深慮慕(mu)容(rong)暐(wei)手(shou)中無實權,而慕(mu)容(rong)評又多猜忌,便對(dui)慕(mu)容(rong)暐(wei)之兄、樂安(an)王慕(mu)容(rong)臧(zang)舉薦吳王慕(mu)容(rong)垂(chui),但是慕(mu)容(rong)臧(zang)沒有聽(ting)從(cong)慕(mu)容(rong)恪(ke)的話(hua)。
慕(mu)容暐親臨慕(mu)容恪(ke)府(fu)向他詢問后事(shi),慕(mu)容恪(ke)再次向慕(mu)容暐推薦慕(mu)容垂,說:“我聽聞,傅(fu)說舉薦士人。板筑之(zhi)人都可(ke)以(yi),更何(he)況(kuang)是(shi)國(guo)家(jia)的懿籓!吳王兼(jian)具(ju)文武(wu)之(zhi)才,才能僅次于管(guan)仲、蕭何(he)。陛(bi)下如果把政務(wu)交給(gei)他,國(guo)家(jia)就能獲得安定。不(bu)然,我怕二寇肯定會有窺窬之(zhi)計。”慕(mu)容恪(ke)言終(zhong)而卒。死后,贈本官,謚(shi)號(hao)為桓(huan)。
慕(mu)容(rong)恪一生(sheng),戰昌(chang)黎、密云,破(po)高句麗、宇文(wen)部,攻石趙殘余,滅冉魏、段齊,討呂(lv)護平野王,擊東晉下(xia)洛(luo)陽,戰功赫赫,構筑了前燕的最(zui)大版(ban)圖。同時,慕(mu)容(rong)儁死后(hou),官拜太宰,輔佐幼主慕(mu)容(rong)暐(wei),以謙恭(gong)寬和的姿態(tai)穩定(ding)國政(zheng),使得國內(nei)相對(dui)穩定(ding)。
慕容皝:“恪智(zhi)勇俱濟,汝其委之。”
王猛(meng):“慕容玄恭,信奇士也,可謂古之遺愛(ai)矣!”
崔浩:“王猛之經國,苻堅之管仲也;慕(mu)容(rong)恪之輔少主,慕(mu)容(rong)暐之霍光也。”
張預:“沉深有(you)大度(du)。......容貌魁杰,雄毅嚴(yan)(yan)重,每(mei)所言及,輒(zhe)經(jing)綸世務,.......數(shu)從皝征伐,臨機多(duo)奇策。......雖(sui)執(zhi)權政事,必諮之于評。罷(ba)朝(chao)歸第,則盡心色養,手不釋卷(juan)。.......恪為(wei)將不尚威嚴(yan)(yan),專(zhuan)(zhuan)以(yi)(yi)恩信御物(wu),務于大略,不以(yi)(yi)小令(ling)(ling)勞眾。軍(jun)(jun)士有(you)犯法,密縱舍之,捕斬(zhan)賊(zei)首以(yi)(yi)令(ling)(ling)軍(jun)(jun)。營內(nei)不整(zheng)似(si)可犯,而(er)防御甚嚴(yan)(yan),終無喪敗。........恪之為(wei)將,專(zhuan)(zhuan)以(yi)(yi)恩信而(er)不尚威嚴(yan)(yan)是(shi)也。”
張預: “孫子曰(yue):‘輔周則(ze)國必強。’恪在(zai)中原,桓溫以(yi)謂(wei)所憂方(fang)大。又(you)曰(yue):‘卒未親附而罰之(zhi),則(ze)不服。’恪之(zhi)為將,專(zhuan)以(yi)恩信而不尚威嚴是也。”
陳普(pu):“霜(shuang)雹風(feng)沙雜亂飛,段龕地(di)下(xia)見春歸。時來但(dan)處周公位,歷舉(ju)華人百世希。”“當時人才南有(you)謝安,北(bei)有(you)慕容恪,西(xi)有(you)王(wang)(wang)猛(meng)。較其分數,玄恭其賢矣,安石(shi)善處轇轕之(zhi)際,富貴之(zhi)心薄而家世清虛,無能遠猷。王(wang)(wang)景略干將吳鉤薄于德矣。玄恭才優而心正,獨(du)不能力主。李績(ji)終(zhong)殺,沈(shen)勁為(wei)可恨。而其討段龕,城下(xia)數語,天地(di)鬼神實聞之(zhi)事。”
張大(da)齡:“慕容氏自(zi)龍驤(xiang)以(yi)(yi)來,世豪東(dong)夏,其(qi)(qi)子孫俱英朗雄(xiong)杰,發在童孺,天之(zhi)(zhi)(zhi)(zhi)(zhi)所(suo)(suo)興,其(qi)(qi)誰廢之(zhi)(zhi)(zhi)(zhi)(zhi)!太(tai)(tai)原德業(ye)邁(mai)於(wu)狐趙,吳(wu)王才(cai)(cai)器不(bu)下管蕭。昔舜(shun)生諸馮,東(dong)夷之(zhi)(zhi)(zhi)(zhi)(zhi)人可(ke)以(yi)(yi)其(qi)(qi)鮮卑而少之(zhi)(zhi)(zhi)(zhi)(zhi)?償恪而不(bu)死,更得明主事之(zhi)(zhi)(zhi)(zhi)(zhi),與吳(wu)王垂左提右挈,驅駕(jia)才(cai)(cai)俊,混一(yi)之(zhi)(zhi)(zhi)(zhi)(zhi)業(ye),指(zhi)顧而定矣(yi)!乃吳(wu)王力足(zu)(zu)以(yi)(yi)討評,而不(bu)為(wei)首亂;時足(zu)(zu)以(yi)(yi)取堅,而還其(qi)(qi)舊(jiu)兵;威足(zu)(zu)以(yi)(yi)困(kun)丕,而開以(yi)(yi)生路,尤人所(suo)(suo)難(nan)者。至於(wu)八十之(zhi)(zhi)(zhi)(zhi)(zhi)齡,取西燕如拾(shi)芥(jie),挫魏(wei)兵如發蒙,真太(tai)(tai)原所(suo)(suo)謂命世之(zhi)(zhi)(zhi)(zhi)(zhi)才(cai)(cai)也。后(hou)(hou)來亡國之(zhi)(zhi)(zhi)(zhi)(zhi)主,猶自(zi)翹然(ran),身在鼎俎,神色不(bu)變(bian)。蓋先世大(da)有功德,故子孫蹶而復奮,不(bu)若諸胡之(zhi)(zhi)(zhi)(zhi)(zhi)一(yi)敗涂(tu)地。予於(wu)和龍之(zhi)(zhi)(zhi)(zhi)(zhi)君(jun),獨有取爾者以(yi)(yi)此。太(tai)(tai)尉裕平燕之(zhi)(zhi)(zhi)(zhi)(zhi)日,欲坑廣(guang)固,得韓范諫而止。嗚呼!燕何(he)罪(zui)哉(zai)!前燕開基(ji),取之(zhi)(zhi)(zhi)(zhi)(zhi)劉石。后(hou)(hou)燕恢復,奪(duo)之(zhi)(zhi)(zhi)(zhi)(zhi)苻秦。燕何(he)罪(zui)哉(zai)!而戮之(zhi)(zhi)(zhi)(zhi)(zhi)若斯之(zhi)(zhi)(zhi)(zhi)(zhi)慘也。太(tai)(tai)尉此舉,不(bu)惟遠愧(kui)三(san)代吊(diao)伐之(zhi)(zhi)(zhi)(zhi)(zhi)師(shi),且近有怍(zuo)於(wu)玄(xuan)恭(gong)景略(lve)矣(yi)。惜哉(zai)!”
《廣(guang)名將傳》:“前(qian)燕(yan)慕(mu)容恪(ke),深沉有(you)略(lve)。皝授(shou)以兵,從(cong)征參酌。使鎮遼東,寇不敢作。嗣雋親(qin)之,立功不薄。俊死暐(wei)孤,復(fu)以后托。有(you)謀中原,桓曰大錯(cuo)。慕(mu)容恪(ke)存,憂方如昨。慕(mu)輿根誅,內(nei)外錯(cuo)愕。恪(ke)獨安(an)之,使人把捉。罷朝而歸,養親(qin)為(wei)樂。臨死薦賢,報(bao)恩急著。忠(zhong)孝若斯,才應(ying)兼學。”
王夫之(zhi):“五胡(hu)旋(xuan)(xuan)起旋(xuan)(xuan)滅(mie),而(er)中(zhong)(zhong)(zhong)原(yuan)之(zhi)死(si)于(yu)兵刃(ren)者(zhe)(zhe)不(bu)可殫計。殫中(zhong)(zhong)(zhong)原(yuan)之(zhi)民于(yu)兵刃(ren),而(er)其(qi)旋(xuan)(xuan)起者(zhe)(zhe)亦必旋(xuan)(xuan)滅(mie)。其(qi)能(neng)有人(ren)之(zhi)心而(er)因以自(zi)全(quan)者(zhe)(zhe),唯慕(mu)容恪乎!故中(zhong)(zhong)(zhong)國之(zhi)君,一姓(xing)不(bu)再(zai)興,而(er)慕(mu)容氏既(ji)滅(mie)而(er)復(fu)起。恪圍(wei)段龕(kan)于(yu)廣(guang)固,諸將請亟攻之(zhi),恪曰:“龕(kan)兵尚眾,未有離心,盡銳攻之(zhi),殺吾士(shi)卒必多矣,自(zi)有事中(zhong)(zhong)(zhong)原(yuan),兵不(bu)暫息,吾每念之(zhi),夜而(er)忘寐,要在取之(zhi),不(bu)必求功之(zhi)速。”嗚呼!惻悱之(zhi)言,自(zi)其(qi)中(zhong)(zhong)(zhong)發,功成而(er)人(ren)免于(yu)死(si),恪可不(bu)謂夷中(zhong)(zhong)(zhong)之(zhi)錚(zheng)錚(zheng)者(zhe)(zhe)乎!”
李鴻章:“為國者,但問(wen)自治,而不依他(ta)人之(zhi)禍福。晉(jin)人喜慕(mu)容儁之(zhi)沒,豈知慕(mu)容恪(ke)之(zhi)更勝。今日急務,莫先儲才。培植人才必以學堂(tang)為根本。”
宋(song)丹(dan)凝:“雖(sui)然慕(mu)(mu)(mu)容(rong)(rong)恪為一代名將,但其(qi)政治(zhi)功績也非常大(da)。在慕(mu)(mu)(mu)容(rong)(rong)儁(jun)死后,慕(mu)(mu)(mu)容(rong)(rong)恪甘為周公,輔(fu)佐幼主慕(mu)(mu)(mu)容(rong)(rong)暐;官(guan)至太(tai)宰,虛懷待(dai)物,知(zhi)人善任;整(zheng)頓吏(li)治(zhi),嚴明賞(shang)罰,謙虛謹慎,從不專斷;誅殺(sha)叛臣(chen)慕(mu)(mu)(mu)輿根,穩(wen)(wen)定朝政。前燕政局的(de)穩(wen)(wen)定,多半是慕(mu)(mu)(mu)容(rong)(rong)恪的(de)功勞。”
梁軍:“慕(mu)(mu)(mu)容(rong)(rong)恪的(de)(de)一(yi)生(sheng),也是前(qian)(qian)燕(yan)由弱變(bian)強(qiang)的(de)(de)一(yi)段時間。他歷事三主,在慕(mu)(mu)(mu)容(rong)(rong)皝(huang)與慕(mu)(mu)(mu)容(rong)(rong)儁(jun)在位時,率軍南(nan)征北(bei)戰,開(kai)疆(jiang)拓土,輔佐幼主慕(mu)(mu)(mu)容(rong)(rong)暐七年(nian)間,前(qian)(qian)燕(yan)政治空前(qian)(qian)穩定,所(suo)(suo)以他在燕(yan)國所(suo)(suo)占的(de)(de)重要地位是不言而(er)喻的(de)(de)。慕(mu)(mu)(mu)容(rong)(rong)儁(jun)死后,東晉認為有機(ji)可乘,桓溫(wen)則說:‘慕(mu)(mu)(mu)容(rong)(rong)恪尚(shang)存,所(suo)(suo)憂(you)方為大耳。’在其(qi)死后,前(qian)(qian)秦(qin)、東晉先后攻打前(qian)(qian)燕(yan),前(qian)(qian)燕(yan)也迅速(su)滅亡,這從另一(yi)方面也反(fan)映出(chu)慕(mu)(mu)(mu)容(rong)(rong)恪對于前(qian)(qian)燕(yan)的(de)(de)重要性。”
萬繩楠:“慕(mu)容恪以其(qi)驚人的戰績,被(bei)后(hou)世譽為‘十六國第(di)一名(ming)將’。”