In the previous chapter the raid on Rhun son of Maelgwn’s kingdom, and his retaliation, was mentioned. The present author has previously placed that invasion in the thirty year range of 543×572 because of the participants, their other activities, and the people they were related to. So how does that fit into the development of British kingdoms in the sixth century? We have already seen the overall picture; kingdoms were getting bigger and their kings were thinking bigger.
There is more to it than that, though. Admittedly, we do not know where all the raiding kings were from, but we do know that a ruler in Strathclyde and another from Lothian came down to northwestern Wales; we know that at least two kings passed through several kingdoms or took very long boat rides to get to Gwynedd. We also know that Rhun responded with his own campaign north.
In the era of Arthur, only decades earlier, kings had made their name by raiding nearby kingdoms and stealing cattle. Their reputations had depended on their ability to steal, and to protect, their livestock. Leaving their kingdoms alone for the days it took to make a raid on a nearby kingdom would have been risky. To travel so far away would have been downright suicidal. That is, until Rhun’s era.
So what changed between the last decades of the fifth century and the middle of the sixth century that made these raids possible? To begin with, it seems likely that the British kingdoms had reached or were reaching their natural limits given the circumstances. By that the author does not mean that the kingdoms had all expanded until their borders were major rivers and mountains. In some cases that was doubtless true, for instance Gwynedd and Stratclyde had the Irish Sea on their west. In this case, though, economics and military practicalities were also involved; think of a kingdom as being only as large as each ruler could protect and keep under their control given the conditions of the time. Horse transportation limited communications and mobility.
Just as important were the traditions of kingship and tribute-giving. Without a very strong one, kings may have needed to keep personal connections with every village under their protection. That meant a limit to how many settlements they could keep.
The time they were living through was even more important. As we have seen, communications had broken down at the end of Roman Britain and were only slowly mending. The rise of kingdoms was helping villages to become more interconnected, but it would have been a slow process. Even in the later Middle Ages travel was limited.
You might ask why a king would not demand tribute from villages he had no intentions of protecting in order to bring in more food and money. For a ruthless modern warlord that might be a good short-term solution, but among the Celts that sort of fraud would not have been in their best interests. As has been seen, to collect tribute would be to claim the area as a part of the kingdom, and if a king was unable to protect his lands he was an ineffective ruler. Among the Celts through the Early Medieval period, an ineffective king could, by tradition and Celtic law, be replaced.
So, what could kings do in the middle sixth century when they realized they could not expand their kingdoms any further but wanted more power? They could get involved with alliances. In the example of Rhun, an alliance served to help each king punish the more powerful Rhun. An alliance might have provided a deterrent against an otherwise more powerful king. It might a king to pass through other kingdoms on his way down to, say, Gwynedd without fear of his own kingdom being attacked. An alliance might also provide trade options and connections to other kingdoms. In short, alliances would have expanded each kingdom’s awareness on the island as they became familiar with their allies’ connections.
The second lesson to take away from the episode between Rhun and the northern allies is the strength of Gwynedd. Five allies made a raid on Gwynedd but Rhun alone took his warriors on campaign up North. The results of that campaign are unimportant. What is essential to understand is that the kingdom was strong enough that Rhun believed he had a reasonable chance of taking retribution on all of the allies and returning home alive. Somehow, the geography of Gwynedd was such that it could support more warriors, or was better organized, or had a better fighting reputation than all five of the northern kingdoms put together.
Professor Charles-Edwards has proposed the intriguing suggestion that the Gwynedd of about 500 may have formed some sort of alliance with the newly powerful Irish Feni in order to gain a reprieve from Irish raids. It is even possible that the Gwynedd dynasty might have been Irish; if it was that might explain the extraordinary lengths to which the dynasty went to portray itself as a native dynasty whose first act was to push the Irish out of Gwynedd. It might also explain the bogus claim that it was descended from Romans and a Gododdin chidftain. Practically speaking, the alliance might have given Gwynedd a distinct advantage for many decades. It might have been the reason behind Rhun’s overconfidence in his army.
The raid on Rhun’s kingdom and his retaliatory campaign up North are two unique events in Early Medieval British history. Studying them gives the historian a snapshot of what the middle sixth century looked like by providing us with many clues about the state of development among the British kingdoms.
It was seen in the introduction that most historians still believe post-Roman Britain was based on the divisions Rome had imposed, which had in turn been based on pre-Roman tribes. What we see here is that this was not always the case. Britain was fractured in 410. Only a century and a half later were its kings capable of thinking and operating much beyond their own borders. In this even the northern kingdoms, which had been freed of Rome soonest and allowed to develop the longest, were not immune.
 Johnson, Hengest, Gwrtheyrn, and the Chronology of Post-Roman Britain, (Madison, 2014), 205-6.
 The Black Book of Chirk states that they arrived by sea but fled by land.
 Legend has it that Rhun died during the campaign. A famous saying is that Rhun’s warriors were gone so long that their wives had to sleep with their servants so that they could have children.
 Charles-Edwards, Wales and the Britons 350-1064, (Oxford, 2013), 175-180.
 Bonedd yr Arwyr, 29.
 “Historia Brittonum”, Nennius: British History and the Welsh Annals, trans. and ed. John Morris, (London, 1980), ch. 62.