At a glance there's no obvious cultural or political reason as to the Asterix adventures would suddenly look to Spain in 1969. The story is set after the battle of Munda and the final defeat of Pompey's supporters which puts the whole of Spain under official Roman control. Although the series hasn't been the greatest for historical accuracy, this does at least fit into an approximate real-world sequence following on from Asterix the Legionary. And perhaps reader (or even teacher) feedback had encouraged Goscinny to adhere more closely to actual dates, explaining why the opening panel sets the story in 45 BC, rather than the more usual rather elastic 50 BC into which the stories are more usually located. But adhering to a real-world timeline has never dictated the settings of adventures before and it's hard to see this as the explanation for this. Perhaps the story was produced to meet the demands of publishers, especially in the wider international market. This was in fact only the second Asterix adventure to be translated into English.
The story's restoration to its original place in the series is a surprise given that it introduces what is one of the most memorable features of life in the Gaulish village and yet it comes over halfway through the original twenty-four stories. Here we meet for the first time the fishmonger Unhygienix, whose wares easily provoke arguments amongst the villagers that can be relied on to lead to a full-on fight. As is usual with the second tier of named villagers, Unhygienix isn't especially developed here but does serve a useful purpose in taking our heroes south to the Spanish border in his boat as well as being the source for plenty of jokes about fish being hired and used for non-food purposes.
The main thread of the story involves the kidnapping of Pepe, the son of a Hispanic chieftain whose village holds out against the Romans. Caesar hopes to bring the mutinous village to heel by holding the boy hostage, sending him to Gaul where he can't be easily rescued. The trope of the lost prince whom the hero(es) must take on a journey back to his own land is a common one in fiction and it was perhaps inevitable that it would show up in the Asterix tales. So too is the presence of an insufferable child who cannot be disciplined because of his rank. Pepe is annoying and selfish, and the plot makes much of this as he proceeds to make life hell first for his Roman captors and then for his Gaulish liberators. As a result almost everyone is privately relieved when another group will have to actually look after him. Unfortunately, his annoyingness spills over, making him a difficult character to care about and thus undermining the effectiveness of the tale.
The first half of the story shows Pepe's capture and then his time in Gaul, with extended scenes devoted to his games, the attempts to recapture him by his Roman warder Spurius Brontosaurus and the Gauls' attempts to make Pepe happy. It's as if Goscinny and Uderzo really want to do more with the villagers and are deliberately delaying getting to Hispania despite the now established pattern of the adventures alternating between Gaul and abroad. This may also explain the slightly bizarre journey made when the Gauls eventually decide they cannot put up with Pepe any longer and must get him back to his village. Unhygienix ferries Asterix, Obelix, Dogmatix and Pepe all the way down the west coast of France but for some unexplained reason he lands them just before the border. This then leads to a sequence as they have to sneak through a mountain pass to avoid Roman patrols. It would have been much simpler if they'd lander on the Hispanic side of the border and the lengthy traffic jam on the Gaulish side could just as easily have been set in Hispania itself.
In 1969 Spain was still under the rule of Franco but experiencing a massive economic boom that saw rapid industrialisation transforming the country. But none of this is noticeable in this story. Instead the ancient Hispania that our visit is a land of badly maintained roads, wild flamenco dancers, bull fights and religious festivals with much of the interest driven by tourism, especially Goths acting in line with stereotypes of German tourists. There's even a mad man trying to recreate the era of chivalry, drawn in the style of Don Quixote. It's not clear if the creators were seeking to avoid commenting on modern Spain because of the Franco regime or were just pandering to dated stereotypes but the result is a rather brief depiction of a backward and superstitious country that doesn't hold up well especially when compared to other foreign trips in the series.
It's very telling that at the end of the story events are suddenly rushed, with Asterix released from captivity for his performance in the arena and the next panel shows him arriving at Pepe's village thanks to directions from Brontosaurus rather than showing any attempt at the journey. The concluding events at the village take about a page as the story rushes to wrap it all up. Overall this story is badly paced and feels like a struggle between competing demands about what to do and where to go, resulting in a drawn-out scene setting followed by a rush through an outdated tourist postcard vision of a country. This is one of the more disappointing tales.