Thank you immensely for the information in your email which I am currently adding to the Beyers Genealogy Project website at www.beyersweb.com
Please excuse me for not mentioning the Dutch line in my original posting, but they are a more recent addition to our research - thus Egbert's information is invaluable.
To clarify further, the Dutch line of 'Beier' did keep in contact with the German line, a branch of which was still based in the region between Boppard and Utrecht as late as 1800.
Violet Middenway married Henry Beyers in Australia in 1881.Violet was the great-grand-daughter of Gerrit Hendrik Middeweg of Utrecht.The Middeweg's were a noble Dutch family with a history of moving between Prussia, Borgholzhausen & Utrecht.
Both the Middenway and Beyers oral histories maintain the families had a long association through a related Beyers line - we assume this is the 'Beier' line based in Utrecht.
Beier was also the name of a small region in south-eastern coastal Denmark during the height of the Viking empire and prior to the Roman Conquest.Research to date suggests these 'Beier' vikings eventually settled in the region that later became Bavaria.It is not clear whether the Dutch Beiers' are later offshoots of the Bavarians or if they originally chose to settle in Holland instead of with the rest of their clan in Germany.
Egbert is correct to warn that there could well be unrelated Beyer family lines in Germany, but this is probably only the case for this surname if the family moved from England to Germany.In England, Beyer, Byers and several other variants are all modern derivatives of the old english for a number of occupations and geographical features.
To date, our research has been able to trace most of the known German lines back to one original line - the Bavarians.The earliest BDM record we have dates around 800 AD for a Beier born in Bavaria.The records for his known children record them as 'Beyer'.
Egbert, the Beyers Genealogy Project would be particularly grateful if you could provide further information - anything you have! - on the De Beyers line.As you said, you guys are very rare and quite intriguing since we know next to nothing about you!