Taken from Wikipedia

Episode 1:

In the series premiere, in 73 B.C., a nameless Thracian warrior and his fellow fighters align themselves with legate Gaius Claudius Glaber and Rome to protect their homeland. But disenchantment with the Romans soon sets in when their allies' strategies leave their homeland unprotected from Getae marauders. The warrior leads a rebellion of the auxiliary troops against the Roman officers, then deserts to return to his village and his wife. He arrives as the Getae attack and he and his wife manage to escape, only to be captured by Glaber the next day. The warrior's wife, Sura, is forced into slavery and he and the other deserters are shipped to the arena in Capua, to be put to death publicly by gladiators, whereupon he proves his worth by defeating all four opponents, and is given a new name, Spartacus.

Episode 2:

The newly enslaved Thracian warrior Spartacus enters the ludus of Lentulus Batiatus to receive gladiator training and discipline. He soon manages to make an enemy of the undefeated Gallic champion of Capua, Crixus, and the attention of whip-wielding taskmaster Doctore who uses harsh methods to test the new novices. He also meets Varro, a Roman gladiator by bankruptcy, who becomes his friend. Spartacus's new owner, the crafty but cash-strapped Batiatus, makes him an offer; if he cooperates and trains as a prized gladiator, he will use his power to help locate his wife. Consequently Spartacus trains to face the test which determines whether he is fit to be a gladiator, and bests Crixus when the Gaul pauses to gloat. Afterwards, the victorious Spartacus swears the sacramentum of the gladiator brotherhood.

Episode 3:

As the gladiators prepare for the series of fights that will be the highlight of the upcoming Vulcanalia festival, Spartacus cleverly manoeuvres to secure the right to battle Crixus, the unbeaten champion of Capua, in the primus or final battle. Despite his wife Lucretia's objections, Batiatus reminds her that Spartacus' bravery and previous exploits have "struck a chord with the public's interest". Meanwhile, Lucretia schemes to win favor with the wife of Gaius Claudius Glaber, the crafty and devious Ilithyia. At a pre-fight banquet, she interests her in the desirous Crixus, although he is secretly enamoured of Naevia, one of the domestic slaves. At the Vulcanalia, Spartacus embarrasses his owners publicly, both by beginning to fight too early, and by surrendering instead of dying.