For many centuries the English/Scottish border was contested territory between the Gael’s, Briton’s, and Pict’s living near to and north of Hadrian’s wall, and the insurgent Angle’s, Saxon’s, Jute’s, and later, Norman’s from the south. Immigration and intermingling of the blood of the families of the border lands was commonplace in the lowlands of Scotland. Mixing of the races was less common among the more easily defended highlands, since the Scot’s (a mixture of the Gael’s from Ireland and native Pict’s) were better capable of defending themselves there, especially since the highlands were probably less appealing to encroachers. The surname Acheson, it has been suggested, might have arisen among the Strathclyde Britons, an ancient and founding Celtic people native to this lowland region of Britain. These tribes of the Briton’s were also swept up in the intermingling of the various racial stocks, and the term Great Britain is ultimately derived from these peoples.
From this smattering of races in Lowland Scotland emerged both the Gordon and Acheson surnames. Whether they were of Anglo-Saxon, Strathclyde British, or Norman origin initially, may never be known with absolute certainty, but it is likely that their later spelling and pronunciation were to some extent influenced by Anglish (spoken) and Norman French (used mainly in court). Variations of the 15th century spelling of Acheson, often ended in -soune, -sone, or -sonne, perhaps thereby exhibiting some Norman influence. This notion is additionally supported by the fact that many of the surnames of early Acheson spouses would also appear to be ultimately of Norman descent.
Due to the heavy intermingling of the races, it is very likely that both Scottish, and Norman blood flowed through the veins of the earliest members of these two border families; and almost certainly had mixed with the blood of other races like the Angles, Saxons and Danes as well.
In any event, the Acheson’s were a Sept of the Clann Gordon in early medieval Scotland, living on the same lands, and fighting the same battles as kin and Clann did. Due to their close physical proximity, Achesons and Gordons certainly intermarried in some instances, both with each other, as well as with other Septs of the Clann. A brief recounting of the surnames of the known Septs (sub-families and/or allied families) of the Clann Gordon follows:

Adam, Adams, Adamson, Addie, Addison, Adie, Aitchison, Aiken, Aitken, Atkin, Atkins, Barrie, Connon, Craig, Cromb, Crombie, Cullen, Darg, Darge, Dorward, Duff, Durward, Eadie, Eddie, Edie, Edison, Esslemont, Gardiner, Gardner, Garioch, Garrick, Garriock, Geddes, Gerrie, Huntly, Jessiman, Jopp, Jupp, Laing, Lang, Laurie, Lawrie, Leng, Marr, Maver, Mavor, Meldrum, Mill, Mills, Milne, Milnes, Moir, More, Morrice, Morris, Muir, Mylne, Tod, Todd, Troup

The number of early Sept surnames of the Gordon Clann was probably much smaller than this list might suggest, considering that many of the surnames are mere repetitions or variations of a single surname. All surnames are ultimately derived from some source though. The source for many surnames is often readily apparent i.e. Adams- a common enough Christian name, Mills- for one who worked a Mill, and More- probably for one who lived near a swamp. Other surnames are not as intuitively obvious. Adie , Atkins and such variants might be from the Adams group of surnames for example. Aitchison (as our name was spelled in this particular Sept list) has also been suggested to be a permutation of the name Adam (a Hebrew name meaning "red skin" or "red earth"- the red earth being that from which Adam was said to have been created).
Truly Adam was a common enough Christian name during the middle ages. It was an especially popular name among the Gordons; ever since Sir Adam Gordon and his Clann participated in the Battle of Bannockburn (1314), and distinguished themselves conspicuously for their service to Robert the Bruce in the battle. The Gordon Clann distinguished itself so well at this battle that the future King, Robert the Bruce awarded Sir Adam and his kin great tracts of formerly Clann McDuff highland lands (the Strathbogie and Cairngorm territories) as previously mentioned. It is supposed that Sir Adam was related to the McDuff’s in some manner anyway, or surely the award of such vast lands would have been more strongly contested (one might also notice that Duff’s were a Sept of the Gordon Clann).
It is conceivable that Aczinson (as well as all of the myriad other early versions of the surname Acheson), could be a permutation, of Adam’s son or even as other historians have suggested, Archie’s son (though doubtful given the preference for Adam among the Gordons). Here I shall endeavour to demonstrate, that the assumption of the "Acheson" surname (and its variants) as a derivation of "Adam", appears to have been an erroneous, though an understandable presumption.
Adam is an ancient name, recorded in the Biblical book of Genesis millennia before this early time period. Knowledge of this name has been passed down from generation to generation basically unchanged for thousands of years (from the Hebrew pronunciation "Adama" it is presently "Adam"). It is difficult to believe that in any Christian society such a well known name (which could be heard in church frequently, or looked up in the Bible at any moment by those capable of reading) could have been slurred so badly that the eventual result would be literally dozens of different forms of the name Acheson that are known to have existed or yet exist today. Use of Latin and Greek variations of Adam can account for some name changes, but this seems particularly improbable, considering that the Clann Gordon and its Septs used the name Adam as both a Christian and surname from the earliest historically recorded centuries in Scotland without any apparent difficulty in spelling it.

A more plausible origin for the surname has been suggested by other surname historians, and can be derived simply from an attempted direct translation of the earliest forms of "Acheson" from the old Anglish language (which had been in use in England for several centuries prior to this period): Ache’s or Acz’s son where Ache or Aeche-Aeche, meaning a descendant of the Anglo-Saxon person named Aecce, Aecc or Aecca, or Aecga or Ecga (which are all derivations from the old Anglish "Ecg", a sword). Acheson would thus roughly translate as "sword son", or perhaps "a son of the sword".
Swords of course would have been a fairly common implement back in the Middle Ages. The prehistoric Anglo name Aecca’s, or Egca’s son might easily have been slurred by both the later Scottish dialect of Anglish, and the Norman French language such that over the centuries it would resemble any number of the variations of the Acheson surname which appeared thereafter. This is particularly believable since after the Norman invasion, the Norman language would almost certainly have influenced its pronunciation. Indeed by glancing at recorded spellings of the late 1400’s and early 1500’s the "Acheson" surname had taken on a more French form of spelling with a softening of the gutteral Scottish consonants and a neo-Norman/French spelling of the "son" ending (i.e. -sone, -soune, -sonne). Harsher early name variants like Aczinson, and Atkinsoun which phoenetically resemble Aecca or Egca’s son, but eventually so often evolved into the softer Achinsounne, and Achesonne variants (approaching the prevalent variants spoken today).

The apparently erroneous assumption that the Acheson surname was derived from the surname Adams is easy to understand, particularly since some of the earliest recorded Atkynsoun’s (and other variants), had father’s named Adam. As mentioned previously, Adam had indeed been a common name within Gordon lands, particularly since 1314, due to Sir Adam Gordon’s leading of the Clann at Bannockburn. One can hardly believe that members of his Clann could so consistently have mispronounced Adams’ son so soon after Sir Adam died (he died in 1333). Previous historians and genealogists, not having explored the Acheson relationship to the early Gordon Clann, and the chief who was perhaps it’s most famous leader, mistakenly took individuals like Johannes filius Ade (1384 in N. Berwick, Scotland) to mean John Adamson, or some such. Though this same individual was again cited in N. Berwick in 1387 by the name John Atkynsoun (who was still hard at work at his customs job). Later this same John/Johannes was once again cited as Johannes filius Ade by additional Latin sources.

Legal and church documents at the time typically used Latin to record information and events. From Latin, "Johannes filius Ade", translates to "John the (natural born) son of Adam". This same sort of Latin citation also occurs reguarding a "Thomas filius Ade" of Bonkyll, Scotland in 1429, but this same Thomas is similarly recorded as Thomas Atkinson by another source. Each of their father’s had simply been named after the popular Christian name of Adam as was particularly in "fashion" among Clann Gordon at this time.
Acheson and many of both the ancient and modern variants appear to be a much closer phonetic derivation from Aecca’s or Ecga’s son than to Adam’s son. The "Aiche" or "Acz" portion of the surname in early citations is much more similar in linguistic pronunciation to names like "Eck"hart, or "Eg"bert than to the "Ad" of Adams.

The Angles and Saxons commenced colonization of the Isle of Britain some time around the 480 to 500 A.D., under the legendary Hengist and/or Horsa, leaving plently of time for a name like Ecg to "evolve" to the variants occuring by the middle ages. Several historical personages used variants of this name, and similar names, in the region of what eventually became the Scottish/English border. A King Ecgfrith was ruler of Northumbria (once part of Scotland) from 670 A.D. to 685 A.D. He being the son of the famous King Oswy/Oswiu of Northumberland.

One of the last powerful Anglo-Saxon Kings of Mercia was a King Ecgfrith (who breifly ruled in the year 796 A.D. when he was probably murdered). His father was Offa, King of Mercia, and first to use the title "King of the Anglish". Similarly the Queen of a King AEthelfrith of Northumbria was named Acha of Diera (ca. 580 A.D.), and the couple is reported to have had 5 sons. These ancient Anglo-Saxon royals are demonstrative of the usage of "Ecg" variants as the first name of a patron/matron. Their descendants might well have incorporated such a name into their surname since as royalty they were individuals of importance. Such names might lend evidence to support a potential origin for the "Acheson" surname variants. If a name like the "Acheson" surname is not derived ultimately from such "Ecg" surnames, then what modern surname does? Surely at least one of these kings must still have male descendants somewhere!

A more likely progenitor for the Acheson surname and its variants is one Arkil Ecgfrith's son, who was a Northumbrian Thane and Chief. This Arkil is said to have fled north into Scotland about 1070 A.D. from the advance of the Norman King William the Conqueror. Ancient Northumbria at its height (in 8th cent.) had been composed of the two preceding Angle Kingdoms of Bernicia and Deira, covering the region of what is today the lowland Berwick, Lanark and Lothiann shires of Scotland (Bernicia-precisely where the Gordons and Achesons first appear in documentation), as well as the counties of Durham and Northumberland in England (Deira). Some of Arkil's descendants went on to become the ancestors of the Earls of Lennox in Scotland, while another descendant "Pharlan" (along a maternal line) went on to become the progenitor of the highland MacFarlane Clann. Obviously therefore, many of these descendants today proudly call themselves Scots.

Arkil's son Alwyn (presently uncertain if he had any other sons) had eight sons of his own, so it is probably safe to assume that Ecgfrith and Arkil have lineal male descendants somewhere. From the old Scottish parish registers and other sources I have not located to date any successive surnames spelled E-c-g, though in Anglo-Saxon AE and E were essentially interchangeable. Ecgfrith and/or Arkil's descendants perhaps initially presumed that they might one day be restored to their Northumbrian lands and titles, so is reasonable to believe that some of Ecgfrith's descendants might have adopted his name as their surname to commemorate their descent, since it is precisely following the Norman invasion that surnames began to arise. This is particularly true since Ecgfrith (presumeably a Thane- as his son Arkil later was) was perhaps descended from the Angle Kings of Northumberland (at least one such King who was mentioned above, was also named Ecgfrith). Additionally, such an individual might easily have proved desireable as a surname progenitor. Later, finding themselves living and marrying primarily amongst Gaelic, Bretonic, and perhaps Norman peoples on a permanent basis, his descendants may have dropped the "-frith" portion of Ecgfrith's son, since it would have so obviously announced their Anglo-Saxon paternal descent ("frith" in Angle meaning simply -wood). Many distinguished Scottish Clanns, Septs and surnames demonstrably evolved in this manner from what were originally non-Celto/Bretonic surnames. In fact from the old parish registers not a single surname occurs of the over 11,000 that uses the frith ending; only the surname "Frith" itself. Instances of the surname "Arkil" itself are similarly documented, though this may have been a fairly common name at one time. Certainly of the countless Anglo-Saxon uses of the -frith ending over the centuries some of their maledescendants ended up in Scotland after being driven out of power by the Normans. It must have been undesireable to announce such paternity in Scotland, since this ending was invariably dropped. Overlay this fact with a little Scottish and Norman language influence, and you might soon arrive at the countless Acheson spelling and pronunciation variations that later occurred.

It should alternately be noted that a simple direct translation from the old Anglish as "sword son" might instead lend us hints into explaining how an early "Acheson" (perhaps the first of the surname in a form recognizable in modern times) came by his surname and/or coat of arms. The Ecg, Egca, Aecca prefix may instead have been given as a result of some military action, as opposed to the more prevalent tradition of paternity.