In the search parameters that folks are using on search engines like Google to get to my website I see a lot of terms indicating they are trying to determine where the name came from and how you are supposed to spell the name. I cringe when I see people asking about the proper spelling of the name.
You see, there is no proper spelling of the name pre-20th century. My own last name is spelled with two T's and yet I always refer to the name on this site as Mathews with one T unless there is a clear indication that a family group always spelled it one way or another. We're dealing with the descendants of people who lived in a time without dictionaries, with very few rules of grammar, little, if any, schooling and who saw no obvious need to spell things much differently from the way they sounded.
Before we get into the spelling variations and how they occured let's first take a look at the different ethnic groups that used the surname of Mathews or some variation of it. My own ancestors originated in the British Isles. Those of us descended from men and women of that geographic community will find various spellings of the surname in that records that exist such as Mathews, Mathewes, Matthews and Matthewes. Another ethnic group with a variation on the Mathews surname is the Scandinavian and Germanic communities. They also have used the surname Mathews as well as close equivalents. Those of Germanic or Nordic origin might use such variations as Mathias/Matthias or Mathieu that eventually evolved into Mathews or Matthews. Another group is the French which use Mathis as their equivalent of Matthews.
As you can see there were quite a few disparate groups who can reasonably be viewed as having names that today may be spelled as some variation of Mathews, but at another time were something a little different.
Surnames are a relatively recent invention for several cultures. Examing the history of exactly when and how various groups came up with the usage of surnames is beyond the scope of this short discussion, but for those of us descended from ancestors in Britain surnames only came about within the last 700 to 800 years. I'm sure we've all seen movies set in medieval times with characters proclaiming themselves as something like "I am David! Son of William!". It was exactly this type of declaration that eventually created surnames. David son of William gave way to David referring to himself as David, William's son and then eventually to David Williamson. This type of naming convention is called patronymic, which in essence means the derivation of a surname from one's father.
The surname "Mathews" and the various other equivalents mentioned such as Matthias and Mathis came about in exactly the same way that David Williamson obtained his surname. The suffix -son is far from the only way to arrive at a surname. Other people used their profession such as a David Carpenter, or a David Cooper, or a David Miller, etc. Other surnames did not change at all from the the spelling of the given name that it was derived from, e.g. surnames such as Thomas or Bryant. Mathews derived from "son of Mathew" by the addition of an s on the end of the name. I have seen nonsense explanations of how "the first" Mathews were the sons of a Sir David Mathew. That's hogwash because Sir David obviously had a surname of Mathew and I'm fairly certain that if his father was named Mathew that there were probably other men in Wales named Mathew who could have just as easily passed that name on to their sons. Sir David may be the first person on record with the mention of the surname, but I can assure you that he was not the originator of the name. This is easily proven by looking at all of the different haplogroups of people with the last name of Mathews (and equivalents thereof) in the Mathews/Matthews/Mathis yDNA group at FTDNA.com. There are just too many people with different deep ancestral origins to have all originated from one person with the surname Mathews. So many different groups had to have originated from not only a different ancestor, but also from a different geographic area. To suggest that they did come from one man is preposterous.
Obviously there are quite a few different Mathews families out there who are not related to each other. From DNA testing we can see that some of us with the surname of Mathews, or any of its variant spellings, are probably more closely related to monkeys than to each other. This means that we are not all descended from the same person going back many hundreds of years. Given the various locales and countries where the name eventually sprang up this is not at all surprising. I'm not going to cover those other locales in my discussion on the spelling variants as there are just too many variables to take into account. Focusing the discussion on my particular line of Mathews, however, should carry over to other lines in the various causes for how and why the spelling variants occured.
Concentrating on the written records left from this country alone, i.e. those of Jamestowne and the original New England communities, we see that several spelling variations appear very early on. It is quite common to see these occur within the same document when referring to the same person even! As noted above people who were able to read and write would commonly spell words of more than just a few characters phonetically. In particular this was true of surnames and words that they didn't spell very often. Spelling conventions and grammar were slow to develop. Who cared if you spelled a man's name as Mathews or Mathewes if it sounded the same either way? Your intended audience would know who you were referring to no matter if you left a letter out here or there (by modern standards) or added another somewhere else. It sounded the same either way. I think it is quite easy to see how this gave rise to the more common variations: Mathews, Matthews, Mathewes, Matthewes, and even simply Mathew.
The Mathis variation in spelling is the one that most Mathews and Mathis researchers have the most trouble picking up when they first start investigating their line. The spelling looks quite a bit different, however the explanation for it is really quite simple: it is the way that the British would have pronounced the name in the early years of settlement of the colonies. In fact, there are places today where "Matthews" is still pronounced "Mathis". In parts of Tennessee and southern Virginia people call themselves "Mathis" everyday, but on paper it's "Matthews". I have seen documents where a single man, Isaac Mathews, had his name spelled three different ways in the same deed. The surveyor wrote the warrant for Isaac Mathews, Isaac spelled his name Matthews when he signed, and the clerk of court wrote Mathis when he entered it into his court record. At other times I have seen where clerks wrote the name as either Mathes or Matthes, but here again both are phonetically equivalent to Mathis which is the way that Mathews was pronounced.
For those people who had some ability to write it is conceivable that they kept seeing their name spelled as "Mathis" by others and eventually decided that is how it should be and from thence they became Mathis even though their brothers and the descendants of those brothers might have called themselves "Matthews".
As you can see there really was no proper way to spell the name you have today by your ancestors. The only way that really matters is how the government knows how to spell your name!