As mentioned elsewhere, the standard history about Sabaens migrating from Yemen to Ethiopia is undergoing major revision. In his book "The Sign and the Seal" (1992) G. Hancock quotes from a paper written by J. Pirenne, an expert on the archaeology of South Arabia, in which she argues that Sabaen civilization was developed in Ethiopia first before crossing the Red Sea to be shared with Yemen:

"--The Sabaens...arrived first of all in Ethiopian Tigray, and entered Yemen via the Red Sea Coast....This conclusion, which is the absolute contrary to all recognized views, is the only one...to explain the facts and do them justice" (1989)

G. Hancock didn't outline the basis of J. Pirennes argument, but considering that she is one of the foremost scholars in interpreting ancient South Arabian inscriptions (she started publishing in the 1950s) it seems natural to assume that she was addressing the problem of the sudden appearance in South Arabia of Epigraphic or Monumental South Arabian (MSA) writing. This pre-Aksumite MSA script also occurs in Ethiopia, however in South Arabia, there is apparently little evidence showing evolution in the lettering style.

Archaeologists expect to see such an evolution if the writing was developed locally. Perhaps J. Pirenne has found this missing evolutionary period in Ethiopia? If so then I suppose the scholars in this field should rename the MSA script as MNE (Monumental North Ethiopian)?

Munro-Hay briefly discusses pre-Aksumite history in his excellent book about Aksum (1991) ---> he mentions research showing that Semitic languages had been around in Ethiopia long before the Sabaens. He also notes the emerging consensus that the Sabaens were probably never a separate ruling class in Ethiopia, and that the distinguishing features of their civilization were quickly absorbed into the pre-existing ancient Ethiopian civilizations.

It should be noted that J. Pirenne also has some far-ranging theories about the original home of the Sabeans --- she links them to northwest Arabia (southern Jordan?) and believes that they came to Ethiopia by way of Egypt to avoid the expansionist Babylonian Kings Sennacherib and Nebuchadnezzar (about 700BC to 600BC). That may be questionable because Nebuchadnezzar was terminated rather suddenly by the Persians as foretold in the Bible (the hand writing on the wall). The Persians were comparatively enlightend rulers and allowed the captives of Babylon to return to their homelands --- so why would the Sabaens continue on an epic journey through Egypt and Sudan when they could've gone home so soon after leaving?

I suppose J. Pirenne advances the northwest Arabian connection because at some point the relationship between the Sabaens and earlier tribes in ancient Mesopotamia and Arabia must be explained? Maybe that's best left until the archaeology of ancient Ethiopia has been thoroughly researched.

Anyway, that is a separate issue from J. Pirennes conclusion that the Monumental North Ethiopian script ~""formerly known as Monumental South Arabian(?)""~ crossed the Red Sea in the Africa to Arabia direction.