Julius Agricola’s First Year As Governor In Britannia And The Submerged Invasion Of Mona


Roman Britannia was ruled by a succession of three great governors in the 70s and early 80s. The first was Petillius Cerialis (r. 71-73), who had some success in curtailing the power of the Brigantes, one of the most powerful peoples in Britain. Although he could not force the Brigantes to fully submit, Cerialis’ governorship was considered a great success. Next, came Julius Frontinus, who governed Britannia between the years 73 and 77. He was something of a polymath and wrote various texts on subjects such as engineering and warfare. He was known to have campaigned in England and Wales during his tenure as governor and his most notable feat was the conquest of the Silures of southern Wales. With such leaders setting the stage, the next governor of Roman Britannia would have a tough act to follow.

In the year 77, Julius Agricola arrived in Britannia to take up the office of governor. Agricola had a decorated résumé—he was the governor of Aquitania from 74-76 and had held the office of suffect consul of Rome in 76 before being sent to govern Britannia. Agricola also had plenty of military experience in Britain. He had served with Governor Suetonius Paulinus during the devastating revolt of Boudicca in 60 or 61. Later, Emperor Vespasian sent Agricola back to Britannia to take up the command of the Twentieth Legion, a post he held from 69 to 73. With such administrative experience, as well as his knowledge of Britain’s geography and people, he was an ideal pick for the job of running Roman operations in Britannia.

For his inaugural year as governor of Britannia, Agricola was eager to prove that he was just as able a warrior as his predecessors. Therefore, he immediately picked up where Governor Frontinus had left off and launched an invasion into Wales soon after taking up his governorship in the year 77. Whereas Frontinus had conquered land in the south of Wales, Agricola targeted un-subdued peoples in central and northern Wales, most notably the Ordovices. Spurned on by reports that the latter group in Wales had annihilated a Roman cavalry squadron, Agricola marched his forces into the territory of the Ordovices and, according to the historian Tacitus, “slaughtered almost the entire nation” (Agricola, section 18).

Despite the subjugation or destruction of the Ordovices in 77, Agricola was not yet done with his inaugural campaign. Instead of marching back to the more secure regions of Roman Britannia, he moved his forces to the northwest. When his army reached the shoreline, only the narrow Menai Strait separated Agricola from his goal—the troublesome island of Mona, now known as Angelsey. Yet, there was a problem. Agricola had begun his campaign as purely a land invasion of Wales and his decision to attack the island came as an impromptu afterthought. Consequently, he had no ships with him when he reached the shores of the Menai Strait. Although Agricola was determined to subdue the rebellious island of Mona, he had no way to transport his troops over the strait.

Unfortunately for the islanders, Agricola found a solution to his dilemma. As the legionnaires and auxiliaries serving in Roman Britannia were drawn from various regions of the empire, Agricola had at his command warriors with all sorts of diverse backgrounds and specializations. One such community that was represented in Agricola’s auxiliary forces was the Batavi, a Germanic people from the Netherlands region who were known to excel at swimming and aquatic warfare.

While the bulk of Roman forces loitered on the shoreline, distracting the nervous inhabitant of Mona, Agricola gathered the Batavi warriors, as well as any other strong swimmers in the army, and gave them a special task to accomplish. While the Roman camp drew the gaze of Mona’s spies and defenders, the elite swimmers of Agricola’s army stealthily plunged into the Menai Strait and swam across to the island. They successfully made landfall without being discovered and crept toward their oblivious opponents. As the warriors of Mona had not taken their eyes off of Agricola’s camp, the islanders were irrecoverably shocked when a force of drenched Roman auxiliaries launched a surprise attack on the unsuspecting defenders. The sudden auxiliary charge caused such chaos that the islanders were said to have immediately surrendered to Agricola.

With the conquest of the Ordovices and the surrender of Mona, Agricola completed his first campaign as governor of Britannia. It was the start of a long and successful tenure that would last until 84, when he was recalled to Rome by Emperor Domitian. During his governorship, Agricola pushed Roman Britannia to the height of its power and he is often remembered as the greatest governor of the province.

Written by C. Keith Hansley.

Picture Attribution: (A statue of Julius Agricola cropped in front of a Roman Legion from Trajan’s Column), c. 16th century, [Public Domain] via Creative Commons).


Leave a Reply