From Encyclopedica Indica

KANISHKA “Hushka, Jushka, Kanishka.” These are the names recorded in the Raja Tarangini of three great Turushka, that is Turk or Tatar, kings, who were of the Buddhist religion. It may, perhaps, be taken for granted that Hushka and Jushka come in their natural succession, for the names might be transposed without detriment to the metre; but the short syllable of the name Kanishka is required where it stands by the rules of prosody, so that the position of the name in the verse is not decisive of his place in the succession of kings. Nothing is known of Jushka beyond the simple recital of his name as above quoted, but the names of Kanishka and Hushka (or Huvishka) have been found in inscriptions and upon coins, showing that their dominions were of considerable extent in Northern India, and that they were, as the Raja Tarangini represents, great supporters of the Buddhist religion. The name of Kanishka has been found in inscriptions at Mathura, Manikyala, Bhawalpur, and Zeda, while his name appears on the corrupt Greek coins as Kenerki. Huvishka’s name has been found at Mathura and on a metal vase from Wardak in Afghanistan; on the coins his name is represented as Oerki. Kanishka preceded Huvishka, and it is certain that their reigns covered a period of fifty-one years, and probably more. The time at which they reigned seems to have been just before the Christian era. A Roman coin of the date 3.3 B.C. was found in the tope of Manikyala, which was built by Kanishka.