A divided kingdom: how a civil war opened Spain to Byzantium

Gold tremissis of Justinus II (565–578), minted in Cartagena (Byzantine Spania), showing the emperor’s bust and Victory with globus cruciger.

In the middle of the 6th century, the Iberian Peninsula looked stable on paper. The Visigoths ruled from Toledo, and Roman structures still shaped daily life. But beneath that surface, the kingdom was fragile—held together by shifting loyalties and contested power.

The crisis began in 548 with the murder of the Visigothic king Theudis. His successor, Theudigisel, lasted barely a year before accusations of licentious conduct led to his own violent end. With the monarchy destabilised, authority splintered and rival factions emerged. One group rallied behind the new reigning king, Agila I, while another coalesced around a challenger, Athanagild, who rose in open rebellion. What began as a contest for the throne soon widened into a broader conflict, particularly in the south of the peninsula, where royal control was weakest and resistance most entrenched.

Athanagild found himself in a familiar dilemma: strong enough to challenge the king, but not strong enough to win. His solution was bold—and risky. He reached out across the Mediterranean to the most powerful ruler of his time: Justinianus I, emperor of the Eastern Roman Empire.

Mosaic of Iustinianus I (Justinian) - San Vitale (Ravenna) - from Wikipedia.

For Justinian, this was not an unexpected request. His reign was defined by attempts to restore Roman authority in the western Mediterranean. North Africa had already been retaken from the Vandals. Italy was being fought over in a long and costly war. Spain, by comparison, was peripheral—but an opportunity like this was hard to ignore.

Around 552, Byzantine forces landed on the southern coast of Iberia. Officially, they came as allies, supporting Athanagild in his struggle. In practice, they behaved as something else: they secured ports, occupied cities, and established a permanent presence.

The civil war eventually ended in Athanagild’s favour. He became king. But the Byzantines did not leave.

Instead, they stayed and organized their holdings into a small province known as Spania. It was not a vast territory. There was no sweeping reconquest, no deep penetration inland. What they held were coastal enclaves—places like Cartagena—linked by the sea rather than by land. From there, they could control routes, project influence, and remain part of Iberian politics without fully dominating it.

For the Visigothic kingdom, this created a new reality. The war had ended, but its consequences lingered. The south was no longer entirely theirs. For decades, a shifting frontier separated Visigothic inland territories from Byzantine coastal strongholds. Conflict, negotiation, and uneasy coexistence followed.

Seen from a wider perspective, the episode fits a broader pattern of the age. Empires did not always expand through overwhelming force. More often, they moved into the cracks—into regions weakened by internal division. Spain in the 550s was one such place.

By the early 7th century, the balance had changed. Visigothic kings gradually regained strength and pushed the Byzantines out. Around 625, the last Byzantine positions in Spain disappeared, almost as quietly as they had been established.

What remained was not a lasting province, but a telling episode: a moment when a civil war opened the door to an empire—and when that empire chose not to conquer everything, but just enough.

Map of the Byzantine Empire in AD 555 (Wikipedia).

Street Art in Cartagena

Street art in Cartagena.

At first glance this corner of Cartagena looks like a forgotten place: crumbling brick walls, fragments of demolished houses, and empty urban space. But look again and the wall begins to speak.

Across the surface runs a collage of murals. A large, fragmented face dominates the centre, emerging from the brickwork as if the building itself were revealing a memory. Around it appear sketch-like figures and smaller portraits, some bold and recent, others faded and partially erased.

Cartagena is a city built on layers of history. Founded by the Carthaginians as Qart Hadasht, it later became the Roman port of Carthago Nova. Yet the wall in this photograph tells a much more recent story.

During the late twentieth century parts of the historic centre declined, leaving empty plots and exposed walls. These surfaces gradually became canvases for urban artists. Festivals such as Mucho Más Mayo helped encourage this transformation, turning neglected corners into open-air galleries.

What makes scenes like this fascinating is their unfinished quality. The murals interact with cracks, repairs and old brickwork. Art and architecture blend together, creating a living canvas that changes over time.

In Cartagena, even a broken wall can become part of the city’s cultural landscape.

The Punic Wars: How Carthage Rebuilt Its Power in Iberia

Image created with AI

Travel today through southern and eastern Spain—from Cádiz to Cartagena, and along the coast near Alicante—and you are moving through landscapes that once played a central role in one of the greatest conflicts of the ancient Mediterranean.

Between 264 and 146 BC, Rome and Carthage fought three major conflicts known as the Punic Wars. These wars determined who would dominate the Mediterranean world for centuries. Yet one of the most important chapters of this story unfolded not in Italy or North Africa, but in Iberia, along the coasts and mining regions of what is now Spain.

The First Punic War

The rivalry began in 264 BC on the island of Sicily. Rome intervened in a local dispute and soon found itself at war with Carthage, the dominant maritime power of the western Mediterranean.

The conflict lasted 23 years. Rome, originally a land power, even built massive fleets to challenge Carthage at sea. In 241 BC, Rome finally won, forcing Carthage to surrender Sicily and pay a heavy indemnity. Soon afterwards Rome seized Sardinia, leaving Carthage weakened and humiliated. The First Punic War

But Carthage was not finished.

Turning to Iberia

After the war the city nearly collapsed during a rebellion of unpaid mercenaries. The general who saved it was Hamilcar Barca, a commander who had fought Rome in Sicily.

Hamilcar understood that if Carthage ever wanted to challenge Rome again, it needed new resources—especially money and soldiers. He found both in Iberia.

Phoenician traders had long been active along the Iberian coast. One of their oldest settlements was Gadir, modern Cádiz, founded centuries earlier as a trading port linking the Atlantic and Mediterranean. But in the 230s BC, Hamilcar began transforming Carthaginian influence in Spain into a real territorial power.

The region’s silver mines filled Carthage’s treasury, and Iberian warriors joined its armies.

Carthaginian Cities in Spain

Hamilcar’s successors continued this expansion. His son-in-law Hasdrubal the Fair founded a new Carthaginian capital in Iberia: Carthago Nova, today’s Cartagena.

The city had an exceptional natural harbor and lay close to the mining districts that financed Carthage’s growing power.

Further north along the coast lay Akra Leuke, usually identified with the area around modern Alicante. According to ancient sources, Hamilcar himself established a Carthaginian base here during his early campaigns in Iberia.

Together with Cádiz and Cartagena, these cities formed the backbone of Carthage’s Spanish power.

Among the young men growing up in this frontier world was Hamilcar’s son: Hannibal.

Hannibal’s Iberian War Machine

Hannibal spent much of his youth in Iberia, surrounded by soldiers and tribal allies from across the peninsula. The armies he would later command included large numbers of Iberian warriors, and Spain’s silver financed his campaigns.

In 218 BC, at the start of the Second Punic War, Hannibal marched from Carthaginian Spain across the Pyrenees and eventually over the Alps into Italy — accompanied, according to ancient accounts, by African forest elephants.

For years he defeated Roman armies, winning famous victories such as Cannae in 216 BC.

Yet even Hannibal could not destroy Rome.

Why Rome Survived

Rome’s strength lay in its political and military system. Roman commanders rotated regularly, creating a steady supply of competent leaders rather than relying on a single genius.

Even more important was Rome’s network of allies across Italy. These communities supplied vast numbers of soldiers, allowing Rome to rebuild its armies again and again.

Over time this system wore Hannibal down. Rome eventually defeated Carthage in 202 BC, and in 146 BC the city itself was destroyed.

Iberia’s Forgotten Role

Today the Punic Wars are often remembered for Hannibal’s dramatic march across the Alps.

But the deeper story runs through Spain.

From the ancient Phoenician port of Cádiz, to the Carthaginian stronghold of Cartagena, and the early military base near Alicante, Iberia became the place where Carthage rebuilt its power after defeat.

It was here that the silver, soldiers, and strategy emerged that allowed Hannibal to challenge Rome—and nearly change the course of Mediterranean history.

Streets that made a city: the Decumanus Maximus and Cardo Salvius of Roman Cartagena

When we think of Roman cities, we tend to think in monuments. But Rome was built first on streets.

In ancient Carthago Nova — today’s Cartagena — two main axes shaped the city: the Decumanus Maximus, running east to west, and the Cardo Salvius, running north to south. Together, they organised movement, power and daily life. Before entering a theatre or a forum, you were already inside Rome simply by walking these roads.

The Decumanus Maxima: an urban spine

The Decumanus Maximus in Cartagena.

The Decumanus Maximus was Cartagena’s main east–west artery. Adapted to a hilly landscape and a busy harbour, it was not a ceremonial boulevard but a working street. Shops opened onto it, carts passed through it, conversations and transactions filled it. This was Rome as routine rather than spectacle.

The Cardo Salvius: life at street level

The Cardo Salvius in Cartagena.

Crossing the decumanus was the Cardo Salvius, the city’s principal north–south street. Its name hints at importance and local pride. Lined with houses, workshops and public buildings, it connected residential areas with the civic and economic heart of the city. This was a street designed for presence, not speed.

Roman Cartagena (Carthago Nova) you can still walk today

What makes Cartagena special is that these streets are still visible. Near Parque de El Lago, sections of both the decumanus and the Cardo Salvius lie exposed at their original level. Wheel ruts, paving stones and drainage lines remain clearly readable. Here, Rome is not imagined — it is encountered underfoot.

Where streets became a city

The intersection of decumanus and cardo was the core of Roman Cartagena. From this logic flowed the forum, the theatre and other monuments. Streets came first; buildings followed.

Rome did not rule only through emperors and armies. It ruled through infrastructure, repetition and familiarity. In Cartagena, that logic is still written in stone.

Cartagena — A City That Doesn’t Reveal Itself at First Glance

Cartagena (Spain).

Cartagena is not a city that flatters you on arrival. You don’t walk into a polished museum town. You arrive in a working port — with container ships, naval docks, faded façades and whole neighbourhoods that seem forgotten by time. Peeling paint, shuttered balconies and crumbling walls sit next to grand buildings that hint at former wealth. The history is everywhere, but it hides behind neglect, dust and industry.

And yet, few cities in Spain carry a deeper past.

Founded by the Carthaginians as Qart Hadasht and later reborn as Roman Carthago Nova, Cartagena became one of the great cities of Hispania, enriched by silver mines and protected by a perfect natural harbour. Romans built theatres, temples and forums — much of which still lies beneath today’s streets.

After Rome came Byzantines, Visigoths and Moors. In the 18th century, the city rose again as Spain’s main Mediterranean naval base. Warships, fortresses and arsenals reshaped the harbour. Cartagena became a military city — and remains one.

Mining brought another boom in the 19th century, followed by decline. When industry faded, whole districts slipped into decay. Only recently has restoration begun, slowly uncovering the buried layers.

Cartagena does not hand you its story. You have to walk its hills, descend into its Roman ruins, explore its civil-war shelters and stand on its harbour quays to understand its power.

It is not pretty in a postcard way. It is raw, complex and monumental.

A city that doesn’t seduce — but rewards.

Sailboats captured against the backlight of the sun, by Pedro Jimenez Vicario. Seen at the Roman Theatre Museum of Cartagena.

A City Woven Around a Theatre: Roman Cartagena Revealed

The Roman Theatre of Cartagena (Spain).

At first glance, Cartagena doesn’t give much away. Traffic, shops, everyday life — and then a doorway draws you inside a modern building that quietly functions as a museum. What begins as an exhibition visit slowly turns into something else.

You move upward first, not down. On the upper floor, a long, enclosed passage opens — a tunnel that leads you forward in time as much as in space. And then, almost without warning, the Roman theatre appears.

You emerge halfway into the structure, suspended between the highest rows of seats and the orchestra below. It is an unusual entrance, and a deliberate one. Rather than discovering the theatre under the city, you enter it within the city — inserted into its surviving geometry.

A Stage for a Rising Empire

The theatre was built at the very beginning of the Roman Empire, during the age of Augustus. Its scale alone tells a clear story. This was not a peripheral town. Carthago Nova was prosperous, strategically located, and confident enough to claim a monumental public building at its core.

Roman theatres were never just places for entertainment. They were instruments of civic identity. To build one was to declare that this city belonged to the Roman world — culturally, politically and socially.

Politics Carved into Space

In antiquity, visitors passed beneath inscriptions honouring the imperial family before taking their seats. The message was subtle but constant: Rome was present here, watching, legitimising, ordering the city’s public life.

Inside, society was arranged in stone. The best seats lay closest to the orchestra, reserved for those whose status mattered. Architecture reinforced hierarchy long before a word was spoken on stage. Even today, standing among the tiers, that logic remains visible and instinctively readable.

Architecture that Directs Attention

Roman theatres are machines for focus. The rising cavea pulls your gaze downward, towards the orchestra and the stage. Movement, sightlines and sound were carefully controlled. Cartagena’s theatre still demonstrates this with remarkable clarity.

Behind the stage once stood a richly decorated architectural façade, filled with columns and statues. Performances unfolded within a setting designed to communicate order, authority and permanence — values Rome was eager to project.

Rediscovered, not Reconstructed

For centuries, the theatre disappeared beneath later construction. Houses, streets and churches reused its stone and obscured its form. It was not dramatically destroyed, but slowly absorbed by the city that grew on top of it.

Its rediscovery in the late twentieth century returned a missing chapter to Cartagena’s story. Today, the museum route does not try to recreate the illusion of a buried ruin. Instead, it guides you carefully into the structure itself, allowing the theatre to reveal its scale and logic gradually.

A City that Faces the Sea

Carthago Nova is a Mediterranean harbour city, outward-looking and well connected. Trade, administration and wealth passes through its port. The theatre belongs to that identity: public, ambitious, confident.

What makes the visit especially powerful is the contrast. Modern buildings press close around the ancient structure. The theatre is not isolated; it coexists with the present. You do not step back into a distant past — you step into a layer of the city that still shapes it.

Rome here is not a postcard ruin. It is architecture that still commands space, attention and meaning.