Cyrus, King of Persia, was called the "Christ," or the "Anointed of God" (Bunsen, Bible Chronology, p. 5, Keys of St. Peter, p. 125). As Dr. Giles says, "Christ" is "a name having no spiritual signification, and importing nothing more than an ordinary surname" (Giles, Hebrew and Christian Records, p. 64, vol. ii). The worshippers of Serapis were called "Christians," and those devoted to Serapis were called "Bishops of Christ" long before the birth of Jesus of Nazareth (Ibid. p. 86; Taylor, Diegesis, pp. 202-206, 407). This fact is amazing. Eusebius, the ecclesiastical historian says, that the names of "Jesus" and "Christ," were both known and honored among the ancients (Eusebius, Eccl. History, lib. 1. Ch. iv.).
Followers of Serapis were called Christians as demonstrated in a letter from Emperor Hadrian to Servianus, 134. (Quoted by Giles, ii p86)
Egypt, which you commended to me, my dearest Servianus, I have found to be wholly fickle and inconsistent, and continually wafted about by every breath of fame. The worshipers of Serapis (here) are called Christians, and those who are devoted to the god Serapis (I find), call themselves Bishops of Christ.