Augustus Caesar describes the Great Replacement, 2000 years before it happened.
From Suetonius:
penelope.uchicago.edu
Augustan Speech preserved by Cassius Dio:
penelope.uchicago.edu
Augustus begs the Roman citizenry to reproduce as their race is dwindling and being replaced by barbarians.
The Venerable Augustus also recognized that rising female power outside the home was resulting in the decline in birth rates.
Napoleon Buonaparte is an early White Identitarian.
Napoleon on the revolt in Martinique:
Theodore Roosevelt:
Julian:
Next maybe I will add some about famous philosophers and thinkers, and then maybe more figures in American history. Feel free to add your own
From Suetonius:
“Considering it also of great importance to keep the people pure and unsullied by any taint of foreign or servile blood, he was most chary of conferring Roman citizenship and set a limit to manumission. When Tiberius requested citizenship for a Grecian dependent of his, Augustus wrote in reply that he would not grant it unless the man appeared in person and convinced him that he had reasonable grounds for the request; and when Livia asked it for a Gaul from a tributary province, he refused, offering instead freedom from tribute, and declaring that he would more willingly suffer a loss to his privy purse than the prostitution of the honor of Roman citizenship. Not content with making it difficult for slaves to acquire freedom, and still more so for them to attain full rights, by making careful provision as to the number, condition, and status of those who were manumitted, he added the proviso that no one who had ever been put in irons or tortured should acquire citizenship by any grade of freedom.”
Suetonius • Life of Augustus
An English translation, linked to the original Latin text. Part of a very large site on classical Antiquity, with many other ancient works.

Augustan Speech preserved by Cassius Dio:
[...]“For you [directed at Romans in the audience], heedless alike of the providence of the gods and of the watchful care of your forefathers, are bent upon annihilating our entire race and making it in truth mortal, are bent upon destroying and bringing to an end the entire Roman nation. For what seed of human beings would be left, if all the rest of mankind should do what you are doing? For you have become their leaders, and so would rightly bear the responsibility for the universal destruction.”
[...]“Bethink you, therefore, what wrath would justly seize the great Romulus, the founder of our race, if he could reflect on the circumstances of his own birth and then upon your conduct in refusing to beget children even by lawful marriages! How wrathful would the Romans who were his followers be, if they could realize that after they themselves had even seized foreign girls, you are not satisfied even with those of your own race, and after they had got children even by enemy wives, you will not beget them even of women who are citizens! How angry would Curtius be, who was willing to die that the married men might not be bereft of their wives! How indignant Hersilia, who attended her daughter at her wedding and instituted for us all the rites of marriage! Nay, our fathers even fought the Sabines to obtain brides and made peace through the intercession of their wives and children; they administered oaths and made sundry treaties for this very purpose; but you are bringing all their efforts to naught. And why? Do you desire to live apart from women always, even as the Vestal Virgins live apart from men? Then you should also be punished as they are if you are guilty of any lewdness.”
“For surely you are not expecting men to spring up from the ground to succeed to your goods and to the public interests, as the myths describe! And yet it is neither right nor creditable that our race should cease, and the name of Romans be blotted out with us, and the city be given over to foreigners — Greeks or even barbarians. […] And do you, then, who are Romans from the beginning and claim as your ancestors the famous Marcii, the Fabii, the Quintii, the Valerii, and the Julii, do you desire that your families and names alike shall perish with you?”
Cassius Dio — Book 56
Part of a complete English translation of Dio. Site contains many Greek and Latin texts, translations and related material.

Augustus begs the Roman citizenry to reproduce as their race is dwindling and being replaced by barbarians.
The Venerable Augustus also recognized that rising female power outside the home was resulting in the decline in birth rates.
Napoleon Buonaparte is an early White Identitarian.
Napoleon on the revolt in Martinique:
Napoleon seems to recognize the Rising Tide of Color despite living during the idiosyncratic retreat of tsunami-doomed shorelines.Well, then, had I been at Martinique, I should also have been on the side of the English, because above all things it is necessary to save one's life. I am for the whites, because I am white; I have no other reason, yet that is reason good enough. How was it possible to grant liberty to the Africans, to men without any kind of civilization, who did not even know what a colony meant, or that there was such a place as France?
Theodore Roosevelt:
Julian:
"Come, tell me why it is that the Celts and the Germans are fierce, while the Hellenes and Romans are, generally speaking, inclined to political life and humane, though at the same time unyielding and warlike? Why the Egyptians are more intelligent and more given to crafts, and the Syrians unwarlike and effeminate, but at the same time intelligent, hot-tempered, vain and quick to learn? For if there is anyone who does not discern a reason for these differences among the nations, but rather declaims that all this so befell spontaneously, how, I ask, can he still believe that the universe is administered by a providence?"
Next maybe I will add some about famous philosophers and thinkers, and then maybe more figures in American history. Feel free to add your own