Dryden, in one of his occasional pieces, represents the Poet's ghost as saying,

"Untaught, unpractis'd, in a barbarous age, I found not, but created first, the stage";

Shakespeare: His Life, Art, And Characters, Volume I. — Part 85

and such has been the common belief. But the saying is far from true; and Shakespeare's ghost must have sipped large draughts of Lethe, to be capable of speaking thus. For, though the least that he did is worth more than all that was done before him, and though his poorest performances surpass the best of his models; it is nevertheless certain that his task was but to continue and perfect what was already begun. Not only were the three forms of comedy, history, and tragedy in use on the English stage, but the elements of these were to some extent blended in the freedom and variety of the Gothic Drama. The usage also of dramatic blank-verse stood up inviting his adoption; though no one before or since has come near him in the mastery of its capabilities; his genius being an inexhaustible spring of both mental and verbal modulation. Nor can all this be justly regarded as any alleviation of his task, or any abatement of his fame. For, to work thus with materials and upon models already prepared, without being drawn down to their level and subdued to their quality, requires, if possible, a higher order and exercise of power than to strike out in a way and with a stock entirely new. And so the absorbing, quickening, creative efficacy of Shakespeare's genius is best seen in this, that, taking the Drama as it came to his hand, a thing of unsouled forms and lack-lustre eyes, all brainless and meaningless, he at once put a spirit into it, tempered its elements in the proportions of truth, informed its shapes with grace and virtue, and made it all alive, a breathing, speaking, operative power. Thus his work naturally linked in with the whole past; and in his hands the collective thought and wisdom of ages were smelted out of the earth and dross wherein they lay imbedded, and wrought into figures of undecaying beauty.

Shakespeare: His Life, Art, And Characters, Volume I. — Part 85

It is indeed true that the Drama shot ahead with amazing rapidity as soon as it came to feel the virtue of Shakespeare's hand. We have nothing more dreary, dismal, and hopeless than the course of the English Drama down to his time. The people would have dramatic entertainments, and hundreds of minds, apparently, were ever busy furnishing them wooden things in dramatic form. And so, century after century, through change after change, the work of preparation went on, still scarce any progress, and no apparent result, nothing that could live, or was worth keeping alive. It seemed as if no rain would ever fall, no sun ever shine, to take away the sterility of the land. Yet all of a sudden the Drama blazed up with a splendor that was to illuminate and sweeten the ages, and be at once the delight and the despair of other nations and future times. All this, too, came to pass in Shakespeare! and, which is more, the process ended with him! It is indeed a singular phenomenon, and altogether the most astonishing that the human mind has produced.

Shakespeare: His Life, Art, And Characters, Volume I. — Part 85