Sidney, Or Sydney, Sir Philip, an English author, born at Penshurst, Kent, Nov. 29, 1554, died in Arnhem, Holland, Oct. 7, 1586. His father, a descendant of Sir William Sidney, chamberlain to Henry II., was in his youth the bosom friend of Edward VI., and during the reign of Elizabeth held for many years the office of lord deputy of Ireland. His mother was the eldest daughter of the ambitious and unfortunate John Dudley, duke of Northumberland, and sister of Robert Dudley, earl of Leicester. At the age of 12 Sidney was sent to the grammar school of Shrewsbury, and in 1569 entered Christ Church college, Oxford. He subsequently studied at Cambridge, and at both universities was distinguished not less for preeminence in manly exercises than in mental accomplishments. In May, 1572, he obtained a license from the queen " to go out of England into parts beyond the seas," in order to perfect his knowledge of the continental tongues. At the court of Charles IX. of France he attracted the attention of the king, who appointed him gentleman in ordinary of his chamber; but the spectacle of the St. Bartholomew massacre induced him to depart abruptly from Paris, and he travelled through Germany, Italy, Hungary, Poland (where he took some part in the skirmishes with the Russians), and the Low Countries. Returning to England at the expiration of three years, he at once took his place among the foremost of the accomplished Englishmen of the time.

The queen showed him special favor, and called him " her Philip," in opposition, it is supposed, to Philip of Spain, her sister Mary's husband. In 1576 he was nominated ambassador to Vienna, ostensibly to condole with the emperor Rudolph on the demise of his father, Maximilian II., but with the secret instruction to cement an alliance of the Protestant states against Spain; a mission which he discharged successfully, gaining the esteem and high praise of the prince of Orange. He returned in 1577, and for the next few years was employed in no important public capacity, partly from his reluctance to give up his literary occupations, and partly, it has been suggested, through the machinations of Lord Burleigh. But he defended successfully the character of his father, whose administration in Ireland had been misrepresented by enemies at court. When admonished by the queen, in consequence of a dispute between himself and the earl of Oxford, of the difference in degree between earls and gentlemen, he replied that, "although Oxford was a great lord by birth, alliance, and grace, yet he was no lord over him; and therefore the difference of degrees between freemen could not challenge any other homage than precedency." Although the answer was taken in good part by the queen, Sidney deemed it prudent to retire for a while from court; and while residing at the seat of his sister, the countess of Pembroke, he wrote his pastoral romance of "Arcadia," which is in prose, interspersed with short poems.

It never received the finishing touches and corrections of the author, and was moreover left incomplete. After circulating in manuscript for several years, it was published by the countess of Pembroke in 1590; and such was its popularity, that previous to the middle of the 17th century upward of ten editions had appeared, and a French translation was published in 1624. To this period also probably belong the "Defence of Poesie," published in 1595, and originally designed as an answer to the attacks of the Puritans, and the series of amatory poems entitled "Astrpphel and Stella" (1591), which recount the author's passion for Lady Rich, sister of Lord Essex, to whom he was at one time betrothed. In the intervals of his literary occupations he participated in courtly pageants and jousts, the most conspicuous of all the brilliant circle who surrounded the throne; and in 1583 he married the daughter of Sir Francis Walsingham, and was knighted. In 1585 he was nominated governor of Flushing, and in the latter part of the year appointed general of horse under his uncle the earl of Leicester, who was sent with a body of English troops to aid the Dutch in their war of independence. Sidney was fast building up a reputation as a skilful general when his career was brought to an untimely close.

On Sept. 22, 1586, a small detachment of English troops under his command unexpectedly encountered 3,000 Spaniards who were marching to the relief of Zutphen, and a desperate engagement was fought under the walls of the fortress, in which the enemy were signally defeated. Sidney, seeing the Spanish leader going into battle lightly armed, was induced by a chivalric spirit of emulation to imitate his example; and after a series of gallant charges, in which he had a horse killed under him, he received a musket ball in his left thigh. While leaving the field, "being thirsty with excess of bleeding," says Lord Brooke, "he called for drink, which was presently brought him; but as he was putting the bottle to his mouth, he saw a poor soldier carried along, who had eaten his last at the same feast, ghastly casting up his eyes at the bottle. Which Sir Philip perceiving, took it from his head before he drank, and delivered it to the poor man, with these words: 'Thy necessity is yet greater than mine.' " He lingered several weeks in great agony, and met his death with Christian serenity, solacing even his last hours with literary composition.

His body was taken to London, and after lying in state was interred in St. Paul's cathedral, Feb. 16, 1587; and a general mourning, the first on record in England, was observed. Spenser has embalmed their mutual friendship in a pastoral ode entitled "Astrophel." Sidney left an only daughter, who became fifth countess of Rutland, but died without issue; and his name is now-represented in the English peerage by Lord De l'Isle, a descendant of his brother Robert. His "Complete Works" were published in 3 vols. 8vo (London, 1725), and his "Miscellaneous Works " were edited with a memoir by W. Gray (Oxford, 1829; reprinted, Boston, 1860). The latest edition of his Works is " The Complete Poems of Sir Philip Sidney," edited by the Rev. A. Grosart, in the " Fuller Worthies' Library," printed for private circulation (2 vols., 1873). - His sister Mary, countess of Pembroke (died Sept. 25, 1621), is intimately connected with his private history. He joined with her in a translation of the Psalter " into sundry kinds of verse," first printed in London in 1823. She wrote an elegy on her brother, a pastoral poem in praise of Astraea (Elizabeth), and a poem " On our Saviour's Passion," preserved in manuscript in the British museum, and published in 1862, besides translating from the French the " Tragedy of Anfonie".