Before we hear of the country Serica, many ancient authors mention the people the Seres, the manufacturers and distributors of the precious material silk. Some geographers believe that the Greco-Romans denominated the Chinese when approached from the Pacific Ocean as Sinae, whereas when reached from the Asiatic steppes they were called Seres. Others contend however, that the Sinae were the Ancient Chinese while the Seres were an assimilated melange of Indo-European and perhaps Turkic people who had formed a loose confederacy and dealt with the Indians, the Chinese and through the Parthians and later the Sassanid Persians, the Romans as well. The descriptive accounts inscribed by Pliny do intimate to us that the Seres were indeed a "Caucasoid" people and whereas some tribes did cohabit with them, they did not constitute the distinguishing strain of the nation. This opinion is substantiated by the portrayal of the Sericans written by Pausanias, which assorts them as being the mixed offspring of the Scythians and the Indians, both Indo-European peoples. Further, in the early 19th Century the celebrated German explorer, cosmographer and natural philosopher Alexander von Humboldt postulated from his researches that, as with the present (both his and ours), Central Asia contained a mixed population of doubtful origin. He specifically cited the Massegetae tribe north of the Oxus River as a Mongolic people cohabiting with the Indo-European Sogdians, Bactrians and Indians (See: Fragments de géologie et de climatologie asiatiques (2 vols. 8vo, 1831), and in central Asia (3 vols. 8vo, 1843). The Serican physiognomy is described as being of extraordinary size, with blue eyes, red hair, a rough voice and a body quite unfamiliar with infirmity or contagion. The final characteristic, most likely the wistful hyperbole of the Mediterranean writer, is probably drawn from the fame of the region's salubrious climate. Once again it is tempting for the modern geographer or ethnologist to correspond the Seres with any number of patently Indo-European tribes with fair complexion enumerated and described by the Ancient Chinese authors. That the description of the Mediterranean authors pertains to an Indo-European people is evident, though the precise extent of Mongolic admixture into the nation has yet to be satisfactorily ascertained or theorized.
The geographical monuments noted by Ptolemy are many and quite significant in his depiction of the country. The northern margin of the nation of Serica was formed by the Altai Mountains, denominated by Ptolemy the Annibi and the Auxacii Montes. The Montes Asmiraei, coincidentally also the name of a Serican district and municipality, are the Da-Uri Chain while the Cassi Montes are believed to be the mountains of the Gobi Desert. Ptolemy names the principal river of the Seres as being the Bautisus, undoubtedly the Hoang-ho or Yellow River which even today dominates the economy, industry and society of northern China. In the time of the Greco-Romans, as it is now to a lesser degree, this river would have afforded speedy transport of goods, intelligence and culture from the central river-valleys of Chinese habitation to the markets of the West. However, owing to the vast, uncultivated and wild tracts of land which this highway of commerce ran through, the fluency of trade was always reliant upon the comity of the Barbarians tribespeople and the mercantile agents' unction. The ancient authors also declaim the tranquil and pleasant climate of Serica and its plenitude in natural resources. Among these stocks, iron, furs and skins, and precious stones receive the most thorough portrayal. The ancients seem to stress the superabundance of these resources in such a sparse and (comparatively) underdeveloped nation, though this may be the hubris of the Mediterranean peoples being displayed.
The Seres and their country were named after the central object whose existence sustained their industry, the "Ser" or Silkworm. Some classicists argue that it is extremely improbable that a nation would desire to be denominated after a class of insect and the eminent 19th Century scholar and orientalist Christian Lassen identified in the sacred books of the Hindus references to the same people which list their national appellation as being the "Caka, Tukhara, and Kanka". Yet this is simply an assumption, corroborated by facts but hardly proved conclusively and the ethnicity may have lent their name to the creature instead of vice versa. As to the stereotypical character of the average Serican, they were universally depicted as a prudent, just and compassionate people, whose genteel natures were addicted to comfort (not luxury), peace and harmony. In commerce they were shrewd, yet still more assiduous and diligent, and we may safely ascribe their success in trade not to subreption or pecculation but to sedulity and vigilance. For the Romans, a long and mutually remunerative commerce with the Seres seemed to be endangered when the brokers of the deals, the Parthians, were usurped by the Sassanids. For the Romans and Indians, and in this regard history too agrees, the Sassanid Persians lacked the justice and gracious majesty of the earlier Persian kings descended from Cyrus. These Neo-Persians were cruel and treacherous in war and society, yet the allure of wealth made them acquiescent, and the Romano-Serican intercourse was not halted by the violent removal of the Parthian brokers for long.
The Greco-Roman writers have preserved the names of over a dozen tribes and fifteen cities of the Seres. From reading their portrayals, it is evident that not all are of the same ethnicity, though they share a common national appellative. The capital of the Seres is denominated Sera, a city whose ruins are more likely to be located in the Xinjiang plains of modern China rather than closer to Beijing . possible candidates include Kashgar, a major mart of Central Asian trade and transnational interaction, and Yarkand, a place of some regional importance. Issedon, the metropolis of the principal Serican nation the Issedones, is thought to have been situated on the eastern declivity of the Pamirs or even the Altai Mountains while the third city of special note, Aspacara, was described as being built near the ultimate source of the Yellow River.