In the World of Darkness and Vampire: The Masquerade, books Cain is made the first vampire by Lilith. I know that parts of this have been taken from older ideas taken from translations of the Bible, but roughly when did writers start making the links between biblical Cain and vampire mythology?
George RR Martin wrote about Cain as the first vampire in the novel Fevre Dream, which was published in 1982. Not sure if anyone predated him.
I heard other things as well, legends that went beyond our oral history back to our ultimate origins in the dim dawn of time itself. Even there I saw the hand of your people, for our myths were taken from your Christian Bible. Brown, who had once posed as a preacher, read me passages from Genesis, about Adam and Eve and their children, Cain and Abel, the first men, the only men. But when Cain slew Abel, he went forth in exile and took a wife from the land of Nod. Where she came from, if the others were the only people in the world, Genesis did not explain. Brown did, however; Nod was the land of night and darkness, he said, and that woman was the mother of our race. From her and Cain are we descended, and thus it is we who are the children of Cain, not the black peoples as some of your kind believes. Cain slew his brother and hid, and so it is that we must kill our distant cousins and hide ourselves when the sun rises, since the sun is the face of God. We remain long-lived, as all men were in the first days described by your Bible, but our lives are accursed and must be spent in fear and darkness. So many of my people have believed, I was told. Others held to different myths, some even accepting the vampire tales they had heard, and believing themselves to be undying avatars of evil.
TL;DR: I could not find the explicit declaration that Cain was a vampire prior to the release of a series of RPG books in 1991. The RPG is called Vampire: The Masquerade [note: when I first wrote this answer, the RPG was not mentioned in the question. The question was later edited to include it.] and was published by White Wolf. The books started the very same setting called World of Darkness in the question.
The RPG has a creation myth that has Cain as the first vampire, with vampirism being a curse God placed upon him (but not the very first curse).
The inspiration probably came from two sources:
- The Bible itself;
- The epic poem Beowulf.
From the Bible, Cain's curse was twofold: he would not gain sustenance from the Earth, and he would be protected against premature death (anyone who harmed him would receive the same harm sevenfold):
11 And so, cursed shall you be by the soil that gaped with its mouth to take your brother's blood from your hand. 12 If you till the soil, it will no longer give you strength. A restless wanderer shall you be on the earth." 13 And Cain said to the Lord, "My punishment is too great to bear. 14 Now that You have driven me this day from the soil I must hide from Your presence, I shall be a restless wanderer on the earth and whoever finds me will kill me." 15 And the Lord said to him, "Therefore whoever kills Cain shall suffer sevenfold vengeance." And the Lord set a mark upon Cain so that whoever found him would not slay him.
Then there is Beowulf:
Till the monster stirred, that demon, that fiend,
Grendel, who haunted the moors, the wild
Marshes, and made his home in a hell
Not hell but earth. He was spawned in that slime,
Conceived by a pair of those monsters born
Of Cain, murderous creatures banished
By God, punished forever for the crime
Of Abel's death. The Almighty drove
Those demons out, and their exile was bitter,
Shut away from men; they split
Into a thousand forms of evil-- spirits
And fiends, goblins, monsters, giants,
A brood forever opposing the Lord's
Will, and again and again defeated.
Cain had killed his only
Brother, slain his father's son
With an angry sword, God drove him off,
Outlawed him to the dry and barren desert,
And branded him with a murder's mark. And he bore
A race of fiends accursed like their father...
Apparently the authors of V:tM liked the idea of Cain being the progenitor of monsters from Beowulf. They had him become the original vampire and created a whole myth around it, in which Cain learns how to overcome the original curse with the help of Lilith. God then offered him salvation three times but Cain refused; finally God gave up on him and made him a vampire.
While it is not outright vampirism, the apocryphal text Life of Adam and Eve, or Apocalypse of Moses, dated from 1st century AD, included the blood drinking in a dream by Eve of the events.
And after this, Adam and Eve were with one another and while they were sleeping, Eve said to Adam her lord: 'My lord, Adam, behold, I have seen in a dream this night the blood of my son Amilabes who is styled Abel being poured into the mouth of Cain his brother and he went on drinking it without pity. But he begged him to leave him a little of it. Yet he hearkened not to him, but gulped down the whole; nor did it stay in his stomach, but came out of his mouth. And Adam said, 'Let us arise and go and see what has happened to them. (I fear) lest the adversary may be assailing them somewhere.'
A depiction of the events appeared in the 1430 "Alba Bible"
Note that this is an apocryphal text, possibly one of the "older ideas taken from translations of the Bible" that you mentioned.
Another apocryphal link is the Book of Enoch
Others say that when the two angels, Shemhazai and Azazel, came down to earth, they were still innocent. But they were corrupted by the demonesses Na’amah and Lilith.
The children they bore were the giants of old, known as the Nefilim, or Fallen Ones. They bore six children at each birth, and in that very hour their offspring stood up, spoke the holy language, and danced before them like sheep. There were said to be sixty in all. These giants had such great appetites that God rained manna on them in many different flavors, so that they might not eat flesh. But the Fallen Ones rejected the manna, slaughtered animals, and even dined on human flesh.
Howard Schwartz, in The Tree of Souls, notes that these Nefilim, noted as eating of "the flesh of men" are also sometimes linked to Cain.
The primary mystery of Genesis 6 is the identity of the Sons of God. Anthropologists have suggested that they may have been a tribe of exceptionally tall and handsome men who appeared and were irresistible to women. But the ancient rabbis were certain that the Sons of God were angels, although an alternate version in Aggadat Bereshit identifies them as the Sons of Cain.
The Aggadat Bereshit is a 10th century commentary on Genesis.