Melchizedek was the great High Priest who was the King of Salem, and to whom Abraham paid tithes, which the Sacred Record says was "one-tenth of all he possessed." The Book of Mormon gives many details of his life not mentioned in the Bible.
Salem is supposed to be the ancient name of the City of Jerusalem, and many students believe it to mean peace. As Melchizedek established peace in his kingdom that lasted all the days of his life, he was called the Prince of Peace. We can better understand why this name was given him when we remember the royal position which he held in addition to him being the High Priest of God's Church. He reigned as King of Salem under his father, who we may imagine was king of the whole land whose capital city was Salem. Thus Melchizedek being a prince by birth and reigning in the City of Peace we can readily see why he was given that name, Prince of Peace. We have a like circumstance recorded in the Sacred Record of the Nephites. A prince reigned as king over the Land of Ishmael under his father. Lamoni, the son of the supreme ruler of all the Lamanites whose court was in the City of Lehi-Nephi, exercised sovereign authority by imperial mandate. (See Alma, Chapter 20)
Abraham, as he beheld in Melchizedek a real prince of peace, desired that he also should be like him, a Prince of Peace. (See, Book of Abraham 1:2)
This Melchizedek, as we have noted, received the High Priesthood, or God's Holy Order, through a Holy Ordinance administered at the hands of his fathers even from Noah down to his day. "And from Noah till Enoch, through the lineage of their fathers; And from Enoch to Abel, who was slain by the conspiracy of his brother, who received the Priesthood by the commandments of God, by the hand of his father Adam, who was the first man," (Doctrine and Covenants 84:14-15).
Thus we see a direct line of succession in the High Priesthood which followed the faithful even from Father Adam down to Melchizedek who was a High Priest in God's Holy Order. The Church of God in those days kept, as it does now, a complete record of them that hold the High Priesthood. In this way, or through it, we see that there are always those who in every dispensation of the Gospel, bear witness of Jesus Christ and of His Atoning Sacrifice. Through the testimony of these High Priests, men in every age of the world have been taught to glorify the Holy Name of God by repentance and continual faith in Him, whereby they might gain a remission of their sins. Before the Savior's birth in the Land of Jerusalem, the inhabitants of the Earth looked forward to His coming, we look back. Both views are equally efficacious, and in them men can see the right way to "enter into the rest of the Lord."
Among the many things which are made known to us in the Book of Mormon concerning Melchizedek and which the Bible makes no mention is that "his people had waxed strong in iniquity and abomination; yea, they had all gone astray; they were full of all manner of wickedness." But, King Melchizedek who also was, as we believe, the Presiding High Priest of God's Church, implored his people to abandon their wicked ways, and turn from all evil unto God who was ready at all times to forgive the truly repentant sinners. The Sacred Record says, "They did repent," and from their righteous behavior thereafter Melchizedek "did establish peace in all his days."