Prominent Soviet specialist in historical linguistics Academician O. Trubachev (1930-2002) in his ‘Indoarica in the Northern Black Sea Region’ analyzed the names of famous places in Taurica, present-day Crimea, and postulated that they were of Proto-Indoaryan origin. (Hence the name of his work – ‘Indoarika v Severnom Prichernomorie’). O. Trubachev stated that his research was a development of the hypothesis of the renowned German linguist Paul Kretschmer (1866 – 1956) who studied the earliest history and interrelations of the Indo-European languages and who was the first to observe the presence of the Indoaryan etymology in the North Black Sea region.
Trubachev discovered tens of the names in and close to Taurica that in his opinion are of the Indoaryan etymology. One example of such a name is ‘Balaklava‘, a settlement near Sevastopol. In the linguist’s opinion, the word is of the same etymology as the name Palakus whom historian Strabo mentions as one of the sons of the powerful Scythian King Skilurus. Skilurus lived in the 2nd century B.C. and his capital was situated also in Taurica/ Crimea a little bit north of Simferopol. In Trubachev’s view, the name Palakus has full correspondence with the ancient Indian word palaka– “defender, protector’, ‘prince, ruler’. Palaka was the name of several Indian princes and it is not accidental that the name Palakus was given to a prince of specifically Tauric/ Crimean Scythians. The name was part of the Tauroscythians’ lexicon and it cannot be explained by the Iranian language.
The name of the famous Scytho-Maeotic Queen Tirgatao of the 5th century B.C. is analogous to the name Tirgutawiya on the tablets from Alalakh of the Mitanny Empire of the 2nd Millennium B.C. As the Wikipedia page states, the Mitanny Empire had very strong Indo-Aryan linguistic and political influences.
By the way, Trubachev also believed that the Rus originated in the area adjacent to Taurica and is associated with the Roxolani. He, unlike other linguists mentioned in the Wikipedia article, argued that the first part of the name Roxolani was of the same etymology as the ancient Indian ruksa– ‘shining’. He viewed the Iranian *гаих$па– ‘light’ as a less likely variant of the Rus’ origin.
“The Roxolani dwelt in the area that coincided with the “Old Scythia” of Herodotus and Sindic Scythia of Pliny – in the lower reaches of the Southern Bug and the Dnieper Rivers where the traces of the Non-Iranian, but of the Ido-Aryan population can be seen,” – wrote Trubachev.
The area just described was also part of the Royal Scythia described by Herodotus as well. Putting all the pieces together, how likely can it be that the Latin title Rex – “king, ruler” (monarch) originated in this very area? Rex- is derived from Proto-Indo-European *h₃rḗǵs and the burial of the First King of Europe was discovered nearby.
Facts like these seem to support several hypotheses mentioned in books like “Royal Scythia, Greece, Kyiv Rus” regarding the etymology of city of Chernigiv and the central figure on the sarcophagus of Yaroslav the Wise (it is described in the ‘Gardariki, Ukraine’ ebook).