Ancient Christian Witness

As seen in Eusebius' Ecclesiastical History

"(1) Simeon Also having died in the manner shown above,
a certain Jew named Justus succeeded him in the episcopate of Jerusalem. There
were great numbers from the circumcision who came over to the Christian faith at
that time, of whom Justus was one." [1]

JNORM888

As found in "book 3"

[1] pages 99-100 by Eusebius in the book "Eusebius Ecclesiastical Historical: complete and Unabridged. New updated edition", translated by by C.F. Cruse, reprinted 1998 & published by Hendrickson Publishers.