Now the success which Justin had as a teacher at Rome had long raised the envy and malice of the heathen philosophers; and, when these new laws against the Christians came out, one Crescens, a philosopher of the kind called "Cynics", or "doggish" (on account of their snarling, currish ways), contrived that Justin should be carried before a judge, on the charge of being a Christian. The judge questioned him as to his belief, and as to the meetings of the Christians; to which Justin answered that he believed in one God and in the Saviour Christ, the Son of God, but he refused to say anything which could betray his brethren to the persecutors. The judge then threatened him with scourging and death: but Justin replied that the sufferings of this world were nothing to the glory which Christ had promised to His people in the world to come. Then he and the others who had been brought up for trial with him were asked whether they would offer sacrifice to the gods of the heathen, and as they refused to do this, and to forsake their faith, they were all beheaded (AD 166). And on account of the death which he thus suffered for the Gospel, Justin has ever since been especially styled "The Martyr."
 
The Martyrdom of Justin Martyr
from SKETCHES OF CHURCH HISTORY by REV. J. C ROBERTSON, M.A.