Then I saw thrones, and they sat on them, and judgment was given to them. And I saw the souls of those who had been beheaded because of their testimony of Jesus and because of the word of God, and those who had not worshiped the beast or his image, and had not received the mark on their forehead and on their hand; and they came to life and reigned with Christ for a thousand years. The rest of the dead did not come to life until the thousand years were completed. This is the first resurrection.
Revelation 20:4
Coming from the discussion on the Millennium (see here for that), this first resurrection is seen as completely fulfilled. No specific date or events are specifically referenced by this, although there could be some natural events that correspond to this, but as the Millennium is fulfilled through the Middle Ages, this places the first resurrection in the past.