"But this neglect by his contemporaries has been compensated by an immense popularity in modern nations. Whilst his books were never known to the world in their own Greek tongue, it is curious that the Lives were translated and printed in Latin, thence into Italian, French and English, more than a century before the original Works were yet printed. For whilst the Lives were translated in Rome in 1470, and the Morals, part by part, soon after, the first printed edition of the Greek Works did not appear until 1572. Hardly current in his own Greek, these found learned interpreters in the scholars of Germany, Spain and Italy. In France, in the middle of the most turbulent civil wars, Amyot’s translation awakened general attention. His genial version of the Lives in 1559, of the Morals in 1572, had signal success.
"King Henry IV. wrote to his wife, Marie de Medicis: “Vive Dieu. As God liveth, you could not have sent me anything which could be more agreeable than the news of the pleasure you have taken in this reading. Plutarch always delights me with a fresh novelty. To love him is to love me; for he has been long time the instructor of my youth. My good mother, to whom I owe all, and who would not wish, she said, to see her son an illustrious dunce, put this book into my hands almost when I was a child at the breast. It has been like my conscience, and has whispered in my ear many good suggestions and maxims for my conduct and the government of my affairs.”
"Still earlier, Rabelais cites him with due respect. Montaigne, in 1589, says: “We dunces had been lost, had not this book raised us out of the dirt. By this favor of his we dare now speak and write. The ladies are able to read to schoolmasters. ’T is our breviary.” Montesquieu drew from him his definition of law, and, in his Pensées, declares, “I am always charmed with Plutarch; in his writings are circumstances attached to persons, which give great pleasure;” and adds examples.
"Saint-Evremond read Plutarch to the great Condé under a tent. Rollin, so long the historian of antiquity for France, drew unhesitatingly his history from him. Voltaire honored him, and Rousseau acknowledged him as his master. In England, Sir Thomas North translated the Lives in 1579, and Holland the Morals in 1603, in time to be used by Shakspeare in his plays, and read by Bacon, Dryden and Cudworth."
You can read the whole essay here: Ralph Waldo Emerson, Plutarch.