Regarding Steiner, he presented 2 seperate concepts (in his anthroposophical doctrine) regarding epochs: first, the "New Age" (having no connection whatsoever with the Age of Aquarius) which he described as the end of the "Kali Yuga", which he gave as beginning in the year 1899. Secondly-and actually not as much emphasized by Steiner as the "New Age"-is the precessionally determined Age of (the constellation of) Aquarius, which according to Steiner would occur in 2375. Note that anthroposophical astrological thinking is completely siderealist (as was Blavatsky's thought as given in the Secret Doctrine and early Theosophy)
I am somewhat confused by Steiner's ideas relating to the astrological age. You state he considered the Age of Aquarius will begin in 2375 CE while other sources state he considered the Age of Pisces only began in 1473 CE.
Steiner refers to the subject of the vernal sun on 13 Feb. 1917:
?We know that now the sun rises in Pisces. Up to the fifteenth century it rose in Aries . . . ? (Cosmic and Human Metamorphosis, 1989, pp. 16-17)
9 Sept. 1924: ?If in the present epoch we look at the point in the heavens where the sun rises on the twenty-first of March, we find behind the sun the constellation of the Fishes (Pisces). The Sun has been rising in this particular constellation for hundreds of years, but always at a different point. Going back a few centuries we find that the point at which the sun rose in spring was still in the same constellation, but if we go back as far as the year 1200A.D., we find that the sun rose in the constellation of the Ram (Aries).? (The Evolution of the Earth and Man, 1987, pp. 155-164)
I certainly never doubted the context would be sidereal for the Theosophists. They held Indian culture in exceptionally high esteem and indeed both Madame Blatavsky and Colonel Olcott went there for an extended period of years. The headquaters of the organisation was based in India. It is little surprise therefore that they preferred an Indian vision of astrology over a western one.
Regarding historical evidence of an ancient (Western) belief in precession connected with new ages (such as around the time of Christ, and the alleged beginning of the "Piscean" Age) I must again refer you to the Fideler book (Jesus Christ the Sun of God);
Ok I will have a look when my budget allows.
The importance of (certain) stars moving into (certain) tropical signs, relative both to mundane and certain esoteric considerations, is an integral element of certain secret teachings (some originating with the immediate followers of Paracelsus), others to be found in certain medieval magical and alchemical (rather than astrological) texts, and referenced in some of the (rare) "flying rolls" connected with the original Golden Dawn, mostly written by Mathers (as I have mentioned in the Stars thread), and a few also by Wynn Westcott. I speculate that such might be the source for Robson's idea (mentioned above by MarkC). I shall here briefly mention that not all "traditional" astrological information is to be found in the works of the out-and-out astrologers of those times: much (very much, actually) other astrologically oriented material is to be found among the alchemists/spagyrists and "hermeticists" and kabbalists, of the period from around 1100 through 1600 AD, and perpetuated within "underground" linneages founded by certain immediate students of those masters.
Thanks thats a useful point to keep in mind.