lower Dnipro region of a fully formed Scythian culture with no local forerunners, and which included a
notable increase in the number of Scythian funerary monuments.[89][19]
The Scythians underwent tribal unification and political consolidation in reaction to the Persian invasion,
and[19] the names of kings who ruled over the Scythians the 5th century BC are known, although it is
unknown whether these kings were ruling only the western regions of Scythia located between the
Danube and Pontic Olbia or over all the Scythians:[19]
Ariapeithes Scyles, the son of Ariapeithes by a Greek woman from Histria
Octamasadas, the son of Ariapeithes by the daughter of the Thracian Odrysian king Teres I.
Octamasadas deposed Scyles and replaced him on the throneThe Scythians also became more active and aggressive around this time, possibly as a result of the
arrival of the new Sauromatian nomadic elements from the east, or out of necessity to resist Persian
expansionism. This change manifested itself through the consolidation of the dominant position of the
Royal Scythians over the other tribes within Scythia and through the Royal Scythians' hold on the
western part of their realm to the west of the Dnipro, where lived the agriculturist populations,
becoming heavier and more oppressive, and the Scythians may also have gained access to
the Wallachian and Moldavian plains at this time, although Oltenia and parts of Moldavia were instead
occupied by the Agathyrsi. Another result of the changes within Scythia during this period was increased
Scythian expansionism:[19][60][153] one of the target areas of Scythian expansionism was Thrace, where the
Scythians seem to have established a permanent presence to the south of the Danube at an early point,
with the Greek cities of Kallatis and Dionysupolis in the area corresponding to the present-
day Dobruja both being surrounded by Scythian territory; and, in 496 or 495 BC, the Scythians raided the
Thracian territories far to the south of the Danube till the Thracian Chersonese on the Hellespont, as an
attempt to secure themselves from Persian encroachment.[43][60][19]
The emergence of the Thracian Odrysian kingdom during the 5th century BC soon blocked the Scythian
advances in Thrace, and the Scythians established friendly contacts with the Odrysians, with the Danube
river being set as the common border between the two kingdoms, and a daughter of the Odrysian
founder king Tērēs I marrying the Scythian king Ariapeithes; these friendly relations also saw the
Scythians and Thracians adopting aspects of each other's art and lifestyles.[43][60][19]
However, at some point in the 5th century BC, the Agathyrsian king Spargapeithes treacherously killed
the Scythian king Ariapeithes.[146][154]