-- Who is depicted?

 Ariston (Greek: Ἀρίστων) was a king of Sparta, 14th of the Eurypontids, son of Agasicles, contemporary of Anaxandrides.

He ascended the Spartan throne around 550 BC, and died somewhat before (Paus. iii. 7) 510 BC. He thus reigned over 30 years, and was high regarded, as evidenced by a public prayer for him to have a son, when the house of Procles had other representatives.

A son, Demaratus, was born, after two barren marriages, by his third wife, whom he obtained, it was said, by a fraud from her husband, his friend, Agetus. (Herod. i. 65, vi. 61-66; Paus. iii. 7.§7; Plut. Apophth. Lac.)

-- Technical/Specification about the statue

 A stele  is a stone or wooden slab, generally taller than it is wide, erected in ancient Western culture as a monument, very often for funerary or commemorative purposes ("grave steles"). Stelae as slabs of stone may also be used for ancient Greek and Latin government notices or as territorial markers to mark borders or delineate land ownership. The surface of the stele may very often have text and/ or have ornamentation. This ornamentation may be inscribed, carved in relief, or painted onto the slab. Traditional Western gravestones may technically be considered the modern equivalent of ancient stelae, though the term is very rarely applied in this way. Equally, stelae-like forms in non-Western cultures may be called by other terms, and the words "stele" and "stelae" are most consistently applied in archaeological contexts to objects from Europe, the ancient Near East and Egypt, China, and sometimes Pre-Columbian America.

-- More about the artist

 We don't know actually who is the artist who made this piece, and we don't have any clue to deduce him or her.