The Lords of the Flame, also called the Lords from Venus — Beings from a previous chain who came to Earth to assist us in our evolution.
“It was during the ... third root-race that there occurred one of the greatest events connected with human evolution — the descent of the Lords of the Flame from Venus. It has already been mentioned that Venus is considerably further advanced in evolution than our earth-chain, and in consequence of that fact many of her adepts are able to move freely about the solar system, and to go and offer assistance wherever it is needed.

The determined effort had been made to bring up the backward members of our humanity, by affording the additional opportunity to those who needed it of running once more through such evolution as the first, second and third rounds can give; and when that was over this further tremendous stimulus of the descent of these Great Ones was brought to bear as a final effort, to individualise as large a number as possible of the more backward entities before what is called “the shutting of the door,” the period when for the sake of further evolution no more entities could be admitted from the animal kingdom into the human.

This band of Great Ones then arrived from Venus and at once took charge of evolution. Their Leader is called in Indian books Sanat Kumara, and with Him came three lieutenants and some five and twenty other adepts as assistants. About a hundred ordinary human beings who were in some way affiliated to these Great Ones, or perhaps had been individualised by Them, were also brought over from Venus, and merged into the ordinary humanity of the earth.

It is these Great Ones who are spoken of in The Secret Doctrine as projecting the spark into the mindless men and awakening the intellect within them. We must not allow ourselves to be misled by this rather curious expression into supposing that the Lords threw some part of Themselves into the human bodies. They acted rather in the nature of a magnetic stimulus; They shone upon the people as the sun shines upon flowers, and drew them up towards Themselves, and so enabled them to develop the latent spark and to become individualised.

Another point worthy of notice is that none of the Lords from Venus took incarnation in our humanity at all. They did not (and indeed could not) take human bodies; They build for Themselves instead vehicles like the highest ideals of the human form in appearance, yet absolutely unlike it in that they were uninfluenced by time and incapable of change or decay. I have myself seen several of these marvellous vehicles, and although they have been worn upon this earth for sixteen million years they still remain precisely as on the day when they were made. They must be regarded as a kind of permanent materialisation; bodies built like statues, and yet to the sight and the touch presenting the appearance of ordinary living men.

I know that in The Secret Doctrine Madame Blavatsky mentions some of the sons of mind, who came to this earth to help, as incarnating among the people whom they were trying to benefit; but she applies this title to the Lords of the Moon as well as to the Lords of the Flame, and it was the former only who entered into ordinary human bodies and so for the time became part of another race. The great Lords of the Flame have done Their work long ago, and most of Them have passed away from us to take up Their tasks elsewhere. Only a very few still remain with us, holding some of the highest offices of the Hierarchy which works for the good of humanity.

But for the help kindly given to us by these great Leaders the world would have been a very different place today. Without Them not only would millions, who became human under the impetus which They gave, be still in the animal kingdom, but all the rest of humanity would be far behind the position in which it now stands. This fourth round is that which is especially destined to the development of the desire-principle in man; it is only in the next or fifth round that he is intended to devote himself to the unfolding of the intellect. Owing, however, to the stimulus given by the Lords of the Flame the intellect has already been considerably developed, and we are therefore for a whole round in advance of where we should have been but for Their help. At the same time it should be said that the intellect of which we are now so proud is infinitesimal compared to that which the average man will possess at the culminating point of the next or fifth round. ” (Leadbeater, Charles, The Inner Life, paragraphs ***-***, double-volume version)
A time-frame is given for the Lords of the Flame.
“...Lords of the Flame, the Children of the Fire-mist, the great beings who came down from Venus nearly eighteen million years ago to help and to lead the evolution of humanity on our chain. These Great Ones did not take bodies from our then entirely undeveloped humanity, but made for themselves bodies in appearance resembling ours by the force of their will, a kind of permanent materialization. At that period, and for long after it, no members of our humanity were sufficiently developed to fill any of the higher offices in this Hierarchy, and consequently we needed and received this help from without. Gradually, as humanity has evolved, it has become more and more able to provide for itself, and the great Lords of the Flame have been set free to go to the help of yet other evolutions.” (Leadbeater, Charles, The Inner Life, page 4, single-volume version)