Asterix goes out to hunt for dinner and meets a Roman patrol. He soundly (and easily) defeats them. They report back to their camp (Compendium) in shambles. Crismus Bonus, Centurion and head of the Roman garrison there, becomes very keen to discover the secret of the Gauls' superhuman strength, sends a spy disguised as a Gaul into the village. The Roman's identity is revealed when he loses his false moustache, but not before he discovers the existence of the magic potion brewed by the Druid Getafix and actually manages to taste some. With that potion, Crismus Bonus believes that he could overthrow Julius Caesar, and become Emperor himself. So he and his second-in-command Marcus Ginandtonicus have Getafix captured in order to get the recipe.
Asterix learns of Getafix's capture and manages to get into the camp of Compendium where Getafix is being held. Finding Getafix, he and Getafix make plans, the first of which is Asterix joining the druid in captivity. Next they both pretend to crack under torture, and the druid demands a list of hard-to-find ingredients for the magic potion; while Crismus Bonus' soldiers try to find the hardest-to-find ingredients, Asterix and Getafix lounge around in comparative luxury enjoying themselves at the Romans' expense. Finally, all the ingredients are found and the potion prepared, but though magical indeed this turns out to be a very different brew — an extremely potent potion that causes the hair and beard of the drinker to begin growing non-stop at a rapid pace. The Romans eventually convince Getafix to make an antidote, and Getafix agrees to do so (though he in fact makes a cauldron of vegetable soup, as the hair potion is about to wear off anyway). At the same time, he also prepares a small quantity of the real magic potion for Asterix to drink. The two then begin bashing their way out of the Roman camp. As they are attempting to escape, they are stopped by a huge army of Roman reinforcements just outside the camp and are captured again.
Just then a clean-shaven legionary informs Crismus Bonus that he is wanted urgently. When the centurion returns to his tent, he finds Julius Caesar there checking on the condition of the area. Upon meeting Asterix and Getafix, Caesar learns of Crismus Bonus' intentions. As punishment, he sends Crismus Bonus and his garrison to Outer Mongolia where there is a barbarian rebellion and then frees Asterix and Getafix for giving him the information, while reminding them that they are still enemies.
Because this is the first album, many story points and characterizations are still in their formative stages. In fact, due to its original, serial nature, some develop and change even as the story progresses:
- The Roman second-in-command changes abruptly a few pages into the story.
- Getafix begins the story living in a cave in the forest and looking much like a stereotypical caveman. He also uses a walking stick.
- Obelix is seen carrying an axe in his first appearance. It is never seen again. He is satisfied with helping Asterix eat just one boar between them.
- Asterix and other villagers appear to be using the potion constantly, yet seeing the potion being made is viewed as an event.
- Fulliautomatix is seen working metal with his bare hands. He also bears no resemblance to his later appearances.
- Cacofonix the bard plays and calls a dance, and at the end is seated at the table at the feast. Later albums established a running gag where he is never allowed to sing, and is tied up and gagged at feasts to prevent this.
- One of the few books where we get to see some of Getafix's other tricks, namely, the hair-growth potion.
- When he is first introduced in the prologue, Caesar has a completely different look than he has in the rest of the series (NOTE: when he appears in the end of the album he already has his new look; this can be seen as an error)
- The book suffers from it expository nature. Being the first book in the series it needs to set up a lot of background story for places and main characters. For this reason it takes time to get going.
- Dutch-Asterix de Galliër in 1966
- English-Asterix the Gaul translated by Anthea Bell and Derek Hockridge for Brockhampton Press in 1969.
- Bulgarian-Астерикс Галския герой
- Russian - Астерикс и