In AD 180, Spanish-Roman General Maximus Decimus Meridius leads the Roman army to a decisive victory against the Germanic tribes near Vindobona, ending a long war on the Roman frontier and winning the favor of the Emperor Marcus Aurelius. Maximus, weary of battle, decides to retire at his Spanish farm estate at the Emperor’s behest, but the Emperor tells him that his son and heir to the throne, Commodus, is unfit to rule and thus appoints him as regent to help save Rome from corruption. Before he makes his decision, Commodus is confronted by his father who tells him that he will not be emperor. Burdened by grief and believing he was never valued by his father, Commodus kills him. After mourning Marcus Aurelius’ death, the new Emperor asks Maximus for his loyalty, but the general suspects foul play and refuses. Soon after, Maximus is arrested and is scheduled to be executed at dawn. Maximus manages to escape and makes the long journey to his farm on horseback, but arrives to find it burnt and his family dead, under orders of Commodus. He buries them and collapses in despair. He is then captured by slavers who take him to Zucchabar, a North African province. He is sold to a man named Proximo, who trains him as a gladiator. There he befriends two of Proximo’s gladiators: a Numidian named Juba and a German named Hagen. Reluctant at first, Maximus is forced to fight in local tournaments. He wins every match because of his superior military skills and traumatized indifference to death. His newfound fame and recognition is brought to Proximo’s attention. Proximo reveals to Maximus that he himself was once a gladiator, and had fought well enough to have gained his freedom. He encourages Maximus to go to Rome and fight in the Colosseum itself, where the Emperor has organized 150 days of games to commemorate his late father. Proximo advises him to “win the crowd” and so earn their respect and eventually his freedom. He could then use this leverage to possibly overthrow or kill the Emperor as part of his plan for revenge. Maximus’ first taste of gladiatorial combat in the Colosseum is depicted as a re-enactment of the Battle of Zama. With his team portrayed as Carthaginian infantry, they defy all expectations and are able (solely due to Maximus’ commands) to defeat “Scipio’s legionaries” who were supposed to obliterate them. A surprised and delighted Commodus comes into the arena to personally congratulate them. Maximus braces himself to kill the Emperor, but at the last moment decides against it because of the presence of Commodus’ young nephew Lucius Verus. He then reveals himself to the startled Commodus and vows to have his vengeance. As the Praetorian Guard prepares to kill him, the crowd chants “Live!” repeatedly, earning their favor and showing their support. Commodus relents and leaves angrily. Next, Maximus is pitted against the formidable Tigris of Gaul, an undefeated gladiator. After a fierce and lengthy duel which Commodus attempted to fix, Maximus is able to gain the upper hand, but spares his opponent’s life despite the crowd’s urging that he kill him. Angered by this action, Commodus berates him, even taunting him with harrowing details of his family’s death. Undaunted, Maximus turns around and walks away. This act of defiance, along with his victory over Tigris, makes him more popular than the Emperor himself. As Maximus is being escorted back to the gladiators’ quarters, his former orderly Cicero approaches him and says that he still has the loyalty of the legions, encamped near Rome. Commodus’ sister Lucilla and the chief senator Gracchus secure a meeting with Maximus, and he obtains their promise to help him escape Rome, rejoin his soldiers, topple Commodus by force, and hand power over back to the Senate. Suspicious, Commodus learns of this plot from Lucilla by threatening young Lucius, then dispatches his men to arrest and/or kill the conspirators. Gracchus is quickly apprehended, while a contingent of Praetorians is sent to Maximus’ quarters. Proximo lets Maximus escape and sacrifices himself and his men (including Hagen) to gain him more time. Maximus reaches the rendezvous point but falls into a trap; Cicero is killed and Maximus is captured. Commodus, desperate and jealous of Maximus’ growing popularity, challenges him to a duel in the Colosseum. Before the fight, and unknown to the crowd, he fatally stabs him in the side to put him at a disadvantage. During the fight, Maximus manages to evade Commodus’ blows and disarm him. Commodus asks the Praetorians to give him a sword, but his request is denied. He produces a hidden stiletto, but Maximus instinctively turns the blade back into his throat, killing him. However, Maximus succumbs to the stab wound, asking with his last words that reforms be made, his gladiator allies freed, and that Senator Gracchus be reinstated. He is then carried away for an honorable funeral as a “soldier of Rome”. Later, Juba revisits the Colosseum at night, and he buries Maximus’ figurines of his wife and son at the spot where he died. He promises that he will see Maximus again, “but not yet”.
罗马帝国“五贤君”时期，将领马克西姆斯（罗素·克劳饰）在征讨日尔曼的战役中立下奇功，受到老皇帝马可·奥勒留（理查德·哈里斯饰）的重视与喜爱。奥勒留属意将身后权柄交予马克西姆斯，再还政于元老院。不料野心勃勃的皇子康茂德（杰昆·菲尼克斯饰）得知后，竟下毒手弑父篡位，并下令将拒绝效忠自己的马克西姆斯满门抄斩。 马克西姆斯逃过了康茂德的捕杀，但家人全部遇害。孤身一人的他沦为奴隶，几经辗转被送到竞技场成为角斗士供 人娱乐。马克西姆斯凭借英勇的气魄和高超的武艺渐渐脱颖而出，终于晋级至罗马的大角斗场，并在大角斗场的第一战中沉着指挥以弱胜强，得到直面皇帝的机会。 康茂德见到马克西姆斯未死，惊骇无已，多次布置欲在竞技场上将其除掉，却始终未能得手，反令马克西姆斯在民众中声威大震，成为一股不可忽视的力量。 此时康茂德的残暴统治激起了帝国上层普遍的恐惧和不满，皇姐露西拉（康妮·尼尔森饰）与几名元老密谋颠覆，和马克西姆斯接洽并达成约定，将解救其出城发动兵变。康茂德闻讯后以外甥的性命相要挟，逼迫姐姐供出全部计划，然后命禁卫军夜袭角斗士会馆，马克西姆斯被捕。 众叛亲离的康茂德欲在角斗场上亲手杀死马克西姆斯以重拾威信。被暗算在先的马克西姆斯英勇奋战，最终与仇人康茂德同归于尽。