The Proto Basques may have had the highest percentage with more than 50%.
The Yamnaya were probably close.
The Proto Celts in general were way up there.
Bohemia – The Boii were of course a Celtic tribe, but due to their reach and lesser known status, I list them to show their presence in Bavaria and a huge part of what is now Eastern Europe such as Silesia.
The Bavarians may have had very high percentages of Rh- blood as well, but at this time, only about 30% of their DNA is Celtic.
Catalonia may or may not have been up there as well.
The Neanderthals may have later evolved into being rh negative.
Sumerians/Mesopotamians
Ancient Hebrews and Bedouins
Silesia, the Scythian colony
In the second half of the 2nd millennium B.C. (late Bronze Age), Silesia belonged to the Lusatian culture. About 500 BC Scyths arrived, and later Celts in the South and Southwest.
Any group high in y-DNA haplogroup R1b
This, of course, includes pretty much all Celtic tribes, present and ancient, as well as their likely ancestor, the Yamnaya
Sardinians, now low in Rh- blood, may have had huge percentages of Rh- blood
The Berbers today are no necessarily high in Rh- blood as was once said – however, there is a chance that throughout the ages there were Berber groups, if now many or most who had significant percentages of Rh negatives among them. Some remnants such as the Aid Haddidu may still be around.
Let’s also now forget, that…
The Guanches of the Canary Islands may only have 16% Rh negatives at this point, but that doesn’t mean that it’s not due to mixing with those coming from the mainland.
Original Guanches are more or less a mix of Berbers and Basques
The Sami of Lapland are only 5-7 percent Rh-…
so why bother and keep bringing them up?
High mtDNA V frequencies for example and other close relations to Basques and other original Europeans.
Btw.: Why do the have indigenous European status while the Basques don’t?
Our research continues and why wouldn’t it?
Connecting the dots of our ancestries responsible for us being Rh- today matters.
What were ancient tribes like?
How were they with each other?
How were they towards outsiders?
Those are subjects that matter in a world where we may or may not enjoy being a part of the herd.