The Adventus Saxonum in the Historia Brittonum

The Historia Brittonum contains a number of statements which allow us to date the Adventus Saxonum:

“Vortigern, however, held power in Britain in the consulate of Theodosius and Valentinian and in the fourth year of his reign the Saxons came to Britain, in the consulship of Felix and Taurus, and in the four hundredth year from the incarnation of our lord Jesus Christ.”

The first consulate of Theodosius II and Valentinian III was in the year 425. That this was the start of Vortigern’s reign is plausible since he was of gen. -3. This would suggest he was probably in his 30s when crowned king. The passage suggests the Adventus occurred in the year 428 which was, indeed, the year of the consulship of Flavius Felix and Flavius Taurus. The last element of the text may be reconciled with this date by suggesting incarnation was an error for Christ’s Passion.

In the Chronicon Britannicum we see the Adventus incorrectly placed one Metonic cycle later in the year 447, see The Adventus Saxonum in the Chronicon Britannicum. The events of 425 and 428 listed in the HB may have been swapped in the mind of the author when he wrote:

“Also, from Stilicho to Valentinian son of Placidia, and the reign of Vortigern 28 years.”

as Flavius Stilicho was consul for the first time in 400.

HB 31 states:

“It came to pass that after this war between the Britons and the Romans, in which the generals were killed, and after the killing of the tyrant Maximus and the end of the Roman Empire in Britain, the Britons went in fear for 40 years.”

Magnus Maximus was executed in 388. 40 years on from that date we arrive at 428, that is at the Adventus, which is described towards the end of the following passage of text:

“Vortigern welcomed them, and handed over to them the island that in their language is called Thanet, in British Ruoihm.”


Arthurian connections with Ewyas and Ergyng

In Culhwch ac Olwen,during his chase, Twrch Trwyth killed Llygadrudd Emys and Gwrfoddw, Arthur’s uncles, his mother’s brothers. The latter name appears in that of Gwrfoddw Hen, king of Ergyng, but he appears to be a later ruler. However, Welsh dynasties often preserved the same name, so Gwrfoddw Hen may have been a descendant. This suggests Eigr, Gwrfoddw’s sister, could have come from that region.

Ergyng may have covered parts of Herefordshire, Monmouthshire and Gloucestershire. The Brut y Brenhinedd calls Eudaf, an ancestor of Arthur, as “Eudaf yarll ergig ac euas”, that is Earl of Ewyas and Ergyng. However, Geoffrey refers to him anachronistically as “Octavius dux Wisseorum”, presumably the territorial name being derived from Welsh Ewyas.

Magnus Maximus had a daughter, named Sevira, by Elen, daugther of Eudaf. It was through Gwrtheyrn’s marriage with Sevira that he gained control of the territory that was to become known as Ewyas. Geoffrey referred to him as the “Consol Gewissiorum”. He invited Germanic warriors to settle in the Abingdon area to help defend attacks on his territory in Ergyng. The ASC confuses this event with the later settlement in Kent. The name for Gwent is easily confused with that for Kent. Gwrtheyrn locating the Gewisse, a Saxon tribe, in the upper Thames valley made logistical sense, as his opponent, Emrys Wledig i.e. Aurelius Ambrosius, was based in the Wiltshire area. Located in that county is the village of Amesbury, formerly known as “Ambres byrig” in the Cartularium Saxonicum.[1] It is likely that the East Wansdyke earthwork was built by the Britons as a defense against attack from the north.

Cerdic is attributed in the Anglo-Saxon Chronicle as the founder of the Wessex dynasty. However, as Dumville has pointed out, his reign started later than the chronicle suggests. In fact, he belonged to a second Wessex dynasty. The first dynasty was founded by the eponymous ruler, Wig/Giwis, the two names being, as Sisam explains, alliterative pairs. His reign was followed by that of Esla/Elesa. The latter is known as Osla Gyllellfawr, whose defeat by Arthur brought the first Wessex dynasty to an end. For obvious reasons, this disaster goes unmentioned in the ASC.

[1] Birch, W. de G., 1887, 178.

The two Macsen Wledigs

The name Macsen Wledig has been applied to two distinct persons. The first individual appears in gen. -7 of HG 2b as Maxim gulecic, see Why Bartrum’s dating … . I believe this individual can be identified with the Roman emperor Constantius Chlorus as explained in the above link.

The opening lines of The Dream of Macsen Wledig from Pen. 4.

The opening lines of The Dream of Macsen Wledig from Pen. 4. (The National Library of Wales)

The Pen. 16 version of The Dream of Maxen Wledig only describes the story up to his stay in Britain. The version in Pen. 4 of the White Book of Rhydderch speaks about his return to Rome, but this continuation is actually referring to the second Macsen.

This is the Western Roman emperor Magnus Maximus born c. 335. He appears in gen. -4 as in the follwing fragment from JC 13.

Gen. JC20 13b
2 Cyndwr Fendigaid
1 Owain
0 Cyngar (m.) Protec
-1 Owain
-2 Miser
-3 Custennin
-4 Macsen Wledig
-5 Maximianus
-6 Constantinus Mawr
-7 Constantius Elen

Cyndwr Fendigaid is St. Kentigern who was the son of Owain ap Cyngar and not Owain ab Urien Rheged. The table is in accord with the birth of Constantius Chlorus’s wife, Helena, between 248 and 250.[1]

[1] Harbus, A., 2002, 13.

Why Bartrum’s dating of the Demetian Arthur is wrong

To understand why there is a problem with the birthdate of Arthur son of Pedr given by Bartrum, i.e. 560, we need to look at a manuscript that mentions this individual. The names in the tables below are in the same order as they occur in HG 2a, namely progressing from the most recent to later individuals. My allocation of the generation numbers are in the first column and they are based on the principle that the generation number of an offspring should be one greater than that of the parent. The generation number in the fourth column are those given by Bartrum. The first table shows the first segment of the Demetian pedigree. The obits shown in the 3rd column are those stated by Bartrum and originate from the AC.

Gen. HG 2a Obit acc. Bartrum Gen. acc. Bartrum Birthdate acc. Bartrum
13 Owain 18 900
12 Elen 929 18
11 Llywarch 904 17
10 Hyfaidd 893 16
9 Tangwystl 15? 790
8 Owain 811 14?
7 Maredudd 796 13
6 Tewdws 12 700
5 Rhain 11 675
4 Cadwgon 11 650
3 Cathen 10 625
2 Gwlyddien 9 600
1 Nowy 9 580
0 Arthur 8 560
-1 Pedr 7 535
-2 Cyngar 6 510

Using my generation numbers, regression analysis of the five obits in the above table give a generation step-size of 28 years. On the basis of this statistical technique and on the assumption that the average life expectancy was 60 years, it follows that an estimate of Arthur’s birthdate is 536, not 560.

Using a much larger database of obits the step-size is 32 years. Indeed, Bartrum states a male generation (the period between the birth of a father and that of his child) is about 33 years whereas a female generation (the period between the birth of a mother and that of her child) is about 20 years. The vast majority of generations in my database are male ones.

The larger database gives Arthur’s birth as occuring c. 487, this being the mid-value in the range for gen. 0. The Demetian Arthur’s birthdate is in the period that one would expect for the individual around whom the Arthurian cycle was built.

Using my generation numbering, Bartum’s estimates for the birthdates from Owain to Cyngar in the above table has an average step-size of 26 years, which is far too small. To achieve a more realistic step-size, he has given a number of parents and offsprings the same generation number, viz. Elen/Owain, Cadwgon/Rhain and Nowy/Gwlyddien. This results in a more satisfactory step-size of 33 years, but at the cost of artificially giving parents and offsprings the same generation number.

The reason why Bartrum’s analysis went astray may have been because he believed that HG 2 was a single pedigree list, whereas in reality it consists of four seperate segments. In the second segment, shown below, he made use of two dateable events, namely the birth of Gwerthefyr and that of Macsen Wledig. In the Harleian document itself there names take the form Guortepir and Maxim gulecic respectively.

Gen. HG 2b Obit acc. Bartrum Gen. acc. Bartrum Birthdate acc. Bartrum
0 Gwerthefyr 6 480
-1 Aergol Lawhir 5 460
-2 Tryffin 4 430
-3 Clodri 4? 440?
-4 Clydwyn 3 410
-5 Nyfed 2 380
-6 Annun Dyfed 2 355
-7 Macsen Wledig 388 1 330

Gildas writing in the 540s in the DE describes Gwerthefyr, whose name takes the form Vortipor, with the words “… though thy head is now becoming grey … though the end of life is gradually drawing near …”. So, Bartrum’s birthdate for him of 480 cannot be too wrong. He errs when he identifies the Macsen Wledig with the Roman emperor Magnus Maximus who died in 388. This forces him to use an average generational step-size for the second segment of 21 years, which is not credible. Again, he circumvents this problem by giving Clodri/Tryffin and Annun Dyfed/Nyfed the same generation number, resulting in a step-size of 30 years.

In this instance the name Macsen Wledig was a reference to the emperor Constantius Chlorus, who died in 306, for the following reasons. He was born in the year 250 and this date falls into the period of my gen -7. His wife was Helena. This tallies with the first part of the Mabinogion tale entitled the Dream of Macsen Wledig  in which  Macsen came to Britain and married Elen Luyddog, the daughter of Eudaf.

It will be noted that there is an anomaly in that Bartrum’s tentative birthdate given to Clodri is 10 years after that of Tryffin who Bartrum believed was his nephew.

The third segment, HG 2c, contains only two names, Protec and Protector. The full pedigree can be seen in JC 13b.

The fourth and last segment, HG 2d, is shown below. Note, the missing names that have been inserted, i.e. Custennin and Macsen Wledig, can be seen in JC 13b.

Gen. HG 2d
1 Eifudd
0 Eiludd
-1 Stater
-2 Pincr misser
-3 [Custennin]
-4 [Macsen Wledig]
-5 Constans
-6 Constantinus magnus
-7 Constantius Elen Luyddog

This segment confirms the identification of the first Macsen with Constantius, as his wife St. Helena has been given the cognomen of Eudaf’s daughter, namely Luyddog.