In the year 1673, Dryden and Rochester were on such friendly terms, that our poet inscribed to his lordship his favourite play of "Marriage à la Mode;" not without acknowledgment of the deepest gratitude for favours done to his fortune and reputation. The dedication, we have seen, was so favourably accepted by Rochester, that the reception called forth a second tribute of thanks from the poet to the patron. But at this point, the interchange of kindness and of civility received a sudden and irrecoverable check. This was partly owing to Rochester's fickle and jealous temper, which induced him alternately to raise and depress the men of parts whom he loved to patronise; so that no one should ever become independent of his favour, or so rooted in the public opinion as to be beyond the reach of his satire; but it may also in part be attributed to Dryden's attachment to Sheffield, Earl of Mulgrave, afterwards Duke of Buckingham, then Rochester's rival in wit and court-favour, and from whom he had sustained a deadly affront, on an occasion, which, as the remote cause of a curious incident in Dryden's life, I have elsewhere detailed in the words of Sheffield himself. Rochester, who was branded as a coward in consequence of this transaction, must be reasonably supposed to entertain a sincere hatred against Mulgrave; with whom he had once lived on such friendly terms as to inscribe to him an Epistle on their mutual poems. But, as his nerves had proved unequal to a personal conflict with his brother peer, his malice prompted the discharge of his spleen upon those men of literature whom his antagonist cherished and patronised. Among these Dryden held a distinguished situation; for about 1675 he was, as we shall presently see, sufficiently in Sheffield's confidence to correct and revise that nobleman's poetry;[1] and in 1676 dedicated to him the tragedy of "Aureng-Zebe," as one who enjoyed not only his favour, but his love and conversation. Thus Dryden was obnoxious to Rochester, both as holding a station among the authors of the period, grievous to the vanity of one who aimed, by a levelling and dividing system, to be the tyrant, or at least the dictator, of wit; and also as the friend, and even the confidant, of Mulgrave, by whom the witty profligate had been baffled and humiliated. Dryden was therefore to be lowered in the public opinion; and for this purpose, Rochester made use of Elkanah Settle, whom, though he gratified his malice by placing him in opposition to Dryden, he must, in his heart, have thoroughly despised.[2]