Discussion of the Saxon Invasion of Britain, Part 2
by Michael Veprauskas

ADVENTUS
SAXONUM
The Historia Brittonum

The next written source that will assist us to date the Adventus Saxonum, is the Historia Brittonum. Generally ascribed to the monk Nennius, it reflects a British tradition of these events, much as Bede's History preserves an English account.  In its initial form, it seems to have been compiled c.830, but was extensively edited in later centuries.  Several Latin versions, in whole or part, have been identified throughout Great Britain and the rest of Europe.  The Historia Brittonum contains several references  to the initial arrival of the Saxons, but one in particular is more exact in dating this event:

"From the beginning of the world to Constantinus and Rufus,  are found to be five thousand, six hundred, and fifty-eight years.

Also from the two  consuls, Rufus and Rubelius, to the consul Stilicho, are three hundred and seventy-three years.

Also from Stilicho to Valentinian, son of Placida, and the reign of Vortigern, are twenty-eight years.

And from the reign of Vortigern to the quarrel between Guitolinus and Ambrosius, are twelve years, which is Guoloppum, that is Catgwaloph.  Vortigern reigned in Britain when Theodosius and Valentinian were consuls, and in the fourth year of his reign the Saxons came to Britain, in the consulship of Felix and Taurus, in the four hundredth year from the Incarnation of our Lord Jesus Christ.

From the year in which the Saxons came into Britain, and were received by Vortigern, to the time of Decius and Valerian, are sixty-nine years."¹³

In the preceding quote from Nennius, the most important item is section four, and concerns both the beginning of Vortigern's reign and the arrival of the Saxons.  The other four sections are peripheral to these two events.  Here, the beginning of Vortigern's reign is linked with the consulship of Theodosius II and Valentinian III, which occurred in 425.  The fourth year of his reign would have been 428, the year of the consulship of Felix and Taurus.¹⁴   The four hundredth year from the "Incarnation" is a misnomer, as 428 was actually the four hundredth year from the "Passion"¹⁵ of Christ. Confusion in dating from the Incarnation and the Passion occurs elsewhere in the Historia Brittonum.

We will not consider the first statement of Nennius for now, as it is not directly related to our dating of the Adventus (but see A Clerical Portrait of Vortigern).

The second section "from the two consuls, Rufus and Rubelius, to the consul Stilicho..." again  represents dating from an important point in Christianity, as the consuls named held there positions at the customary time for the Passion, AD 28/29.  The Latin text reads "Item a duobus Geminis Rufo et Rubelio...", "from the two Gemini".  This refers to Lucius Rubellius Geminus and Gaius Rufus Geminus who held the consulship in AD 29.  Consuls took office on January 1, of a given year and so consular dating is from January 1st.  The church dated the New Year from March 25th, thus creating a slight ambiguity in dating.  Three hundred, and seventy-three years added to this would bring us to the year 401/402, when Stilicho was regent to the young Honorius.  His actual consulship was in the year 400.  A one to five year dislocation of years is common in old chronologies.  Even Bede erred on several occasions in this respect.  The point is that an important Christian event is linked with Stilicho and Honorius, the latter immediately preceding the reigns of Valentinian III and Vortigern (except for a very brief reign by Constantius).

"Also from Stilicho to Valentinian, son of Placida, and the reign of Vortigern, are twenty-eight years."

Here again, the reign of Vortigern is clearly linked with that of Valentinian III.  Stilicho became regent of Honorius, and hence of the Western Roman Empire, in 395.  His consulship was in the year 400.  Adding 28 years to either of these two dates takes us close to the year 425.

"And from the reign of Vortigern to the quarrel between Guitolinus and Ambrosius, are twelve years, which is Guoloppum, that is Catgwaloph."

As can be seen, all of the preceding calculations start from the beginning of an individuals reign, rise to power, or consulship.  From the earliest times when chronology was based on a prominent individual or event, it was always from its first year.  Certain parties have expressed confusion, about whether this statement should be taken to mean the beginning of Vortigern's reign, or its end.  The beginning is clearly indicated.  The year is about 437.

The last and fifth section, which comes after the central events in section four (Vortigern and arrival of Saxons), starts from the beginning of an event (arrival of the Saxons) and moves backwards in time.  If we amend 69 years to 169 years we arrive at the end of the reign of Valerian, 259/60 ad.  Valerian vigorously renewed the persecutions first set in motion by the Emperor Decius a few years before.  Hence the two names are linked.

It can be seen that this section of Nennius faithfully expresses a unity of purpose, both leading to and from two key events.  That is, the rise of Vortigern and the Adventus Saxonum, the latter of which is dated to 428.  The rise to power of Vortigern, in 425, makes his marriage to Severa - the daughter of the usurper Magnus Maximus (died 388), quite possible.  This is explicitly stated in the well-known pillar of Eliseg.

There are several other sections from the Historia Brittonum relative to our quest.  The first is as follows:

"After the above-said war between the Britons and the Romans, the assassination of their rulers, and the victory of Maximus, who slew Gratian, and the termination of the Roman power in Britain, they were in alarm forty years. Vortigern then reigned in Britain..."¹⁶

The Historia  indicates the termination of Roman authority in Britain occurred during the usurpation of Maximus.  Magnus Maximus revolted and slew Gratian in 383.  He drove Valentinian II from Italy in 387.  In 388, he was defeated and executed by Theodosius I.  If we add 40 years to any of these dates, as indicated by the text, we arrive at the years 423-428 and the reign of Vortigern.  The tradition related here appears distinct and independent from the latter section of Nennius previously quoted.

Elsewhere we read:

"When Gratian Aequantius was consul at Rome, because then the whole world was governed by the Roman consuls, the Saxons were received by Vortigern in the year of our Lord four hundred and forty-seven..."¹⁷

The translation above, by J.A. Giles, diverges from the Latin texts which clearly give the date as "three hundred and forty-seven years", as the time of arrival of the Saxons.  Presumably, he amended the text by a hundred years to put it roughly in line with Bede's Adventus Saxonum, as 347 years was plainly wrong!  The original text also reads "347 years" as dating from the Passion.  To this we arrive at a corrected date of  375 or 379, depending on whether the original source used 28 or 32 ad. as the date of the Passion.  Two of the most common corruption of Roman numerals are "V" with "X" and "L" with "C", especially when the latter "C" is written in the early square form.  The original date could very well have been "CCCXCVII (397) years from the Passion".  Adding 28 or 32 years to this would give a date of 425-429, which fits well with our previous calculations for Vortigern and the Adventus.  The name of the Emperor Gratian would  have been added as reigning during the years 375-379 of the corrupted text.

Using Geoffrey's method of dating Camlann as 93 years after the Adventus, we arrive at the year 521 for this event.  This fits well with the conjectured rise to power of Maelgwn of Gwynedd, around the year 520, and his later supremacy among the British.  The Annales Cambriae date Badon some 21 years before Camlann.

Next: Adventus Saxonum Part Three

12. Geoffrey of Monmouth, History of the Kings of Britain, xi.2.
13. Nennius, Historia Brittonum, Section 66.
14. Leslie Alcock, Arthur's Britain,  p. 104-105.
15. Leslie Alcock, Arthur's Britain,  p. 104-105.
16. Nennius, Historia Brittonum, Section 31.
17. Nennius, Historia Brittonum, Sections 50 and 31, translation by J.A. Giles.