西晋统一不过数十年，八王之乱便掏空了国力。永嘉年间，匈奴刘曜、羯人石勒等相继起兵，洛阳陷落，数年后长安也失守，中原士民大批南渡，史称“永嘉之乱”。
The Western Jin had been unified for only a few decades when the War of the Eight Princes drained its strength. During the Yongjia era, Liu Yao the Xiongnu and Shi Le the Jie rose one after another; Luoyang fell, and a few years later Chang’an too. Great numbers of northern gentry and commoners fled south — an upheaval known as the Yongjia disaster.
在这场大乱之前，祖逖与刘琨同任司州主簿。二人“情好绸缪，共被同寝”，夜里听到荒鸡啼叫，祖逖一脚踢醒刘琨，说：“此非恶声也。”随即起身舞剑。
Before that catastrophe, Zu Ti and Liu Kun both served as clerks in Sizhou. The two were “fast friends who shared a quilt and slept side by side”; hearing a rooster crow in the night, Zu Ti kicked Liu Kun awake and said, “This is no evil sound,” and at once rose to practise swordplay.
荒鸡本是人们忌讳的凶兆，祖逖却把它翻转为催促自己上进的号令。这一细节之所以流传，正因为它写尽了两人不肯虚度光阴的性情。
A rooster crowing out of season was normally a sign people dreaded, yet Zu Ti turned it into a summons to self-improvement. The detail survived precisely because it captures how unwilling both men were to let a single hour go to waste.
刘琨一生以雄豪自许，“枕戈待旦，志枭逆虏，常恐祖生先吾著鞭”。后来他孤守并州晋阳，在胡骑环伺中支撑了近十年，终究兵败，投奔段匹磾后遇害。
Liu Kun saw himself as a man of heroic mettle: “I rest my head on my spear and wait for dawn, resolved to destroy the rebels — my only fear is that Zu Ti will beat me to the whip.” He went on to hold Jinyang in Bingzhou alone, enduring nearly ten years surrounded by nomad cavalry, until defeat forced him to seek refuge with Duan Pidi, who had him killed.
祖逖的北伐则始于建兴元年。朝廷只给了他千人粮、三千匹布，不给铠仗，他仍带着百余家部曲渡江。船到中流，他击楫而誓：“祖逖不能清中原而复济者，有如大江！”
Zu Ti’s northern expedition began in the first year of Jianxing. The court granted him only grain for a thousand men and three thousand bolts of cloth, with no armour or weapons, yet he crossed the Yangtze with a hundred-odd households of retainers. Midstream he struck the oar and swore: “If Zu Ti cannot clear the Central Plains and cross back, may he be as this great river!”
渡江之后，他屯驻淮阴，起炉铸兵，招募到两千余人，逐步推进到黄河以南。他劝课农桑、宽刑薄赋，甚至收葬战乱中的枯骨，百姓作歌称颂；连石勒也修葺他母亲的坟墓，与他通使互市。
After crossing, he camped at Huaiyin, built furnaces and cast weapons, recruited more than two thousand men, and pushed steadily to the south of the Yellow River. He promoted farming, lightened punishments and taxes, and even buried the unclaimed bones of the war dead; the people sang his praises. Even Shi Le repaired his mother’s grave and opened trade and envoys with him.
然而东晋朝廷对他始终猜忌，派戴渊节制其军，又逢王敦之乱将起，祖逖忧愤成疾，于太兴四年病逝于雍丘，年仅五十六岁。他收复的河南之地很快得而复失。
Yet the Eastern Jin court never ceased to suspect him. It placed Dai Yuan over his army, and with Wang Dun’s rebellion brewing, Zu Ti fell ill from grief and anger and died at Yongqiu in the fourth year of Taixing, only fifty-six. The Henan lands he had recovered were soon lost again.
“闻鸡起舞”与“中流击楫”从此成为中国人讲立志与自律时最常引用的两个画面：成功未必如约而至，但奋发必须从每一个清晨开始。
Ever since, “rising at cockcrow to practise” and “striking the oar midstream” have been two of the images Chinese most often invokes when speaking of resolve and self-discipline: success does not always arrive as promised, but striving must begin with every dawn.