HENRY IV (1367–1413), king of England, eldest surviving son of John of Gaunt [q. v.], fourth son of Edward III, by his first wife, Blanche, daughter and heiress of Henry, duke of Lancaster [q. v.], was born on 3 April 1367, the day of the victory won at Najara by his father and his uncle Edward the ‘Black Prince’ [q. v.] (Notes and Queries, 4th ser. xi. 162), at his father's castle of Bolingbroke, near Spilsby, Lincolnshire (Capgrave, De Illustribus Henricis, p. 98). He was therefore sometimes called Henry of Bolingbroke (Williams, note to Chronique de la Traïson, p. 124). Contemporaries more often styled him Henry of Lancaster. When only ten years old he was, on 23 April 1377, made a knight of the Garter by his grandfather Edward III. Less than three months afterwards he bore the principal sword at the coronation of Richard II (Fœdera, vii. 160, original edition). In 1377 he was already styled Earl of Derby.
Henry's mother died in 1369. In 1372 his father married Constance of Castile, and called himself king of Castile and Leon. When, about June 1378, John went beyond sea he appointed Henry ‘warden of the regality of the palatine county of Lancaster’ (Deputy-Keeper's Thirty-second Report, p. 350). About 1380 Henry married Mary Bohun, the younger of the two coheiresses of the Hereford earldom, whose elder sister was already the wife of his uncle Thomas of Woodstock [q. v.], afterwards Duke of Gloucester. Both were mere children. In 1381 Henry was with King Richard in the Tower when threatened by the followers of Wat Tyler (Knighton in Twysden, Decem Scriptores, c. 2634). In 1382 his wife was still under the care of her mother, the Countess of Hereford (Fœdera, vii. 343). Yet on 4 Nov. 1383 he was associated with his father, already lieutenant in Picardy, on a commission to treat with Flanders and France at Leulinghen (ib. vii. 412–413). When he was less than twenty Froissart praised his knightly skill, and in 1386 he distinguished himself in some great jousts at London.
In July 1386 John of Gaunt, when sailing in quest of his throne, was accompanied by Henry to Plymouth (Knighton, c. 2676). Henry was again warden of the Lancaster palatinate, and witnessed charters between 1 Sept. 1386 and December 1388 (Deputy-Keeper's Thirty-second Report, App. i. pp. 359–361; Froissart, xi. 325, ed. Kervyn). He probably continued in office until his father's return in November 1389.
The struggle between Richard II and the baronial opposition began in the parliament of October 1386, when Henry was not of age to receive a summons. Yet when, after Easter 1387, Richard withdrew to Wales to take counsel with Robert de Vere, duke of Ireland [q. v.], Derby was one of the persons obnoxious to the king and his favourites (Walsingham, Hist. Anglic. ii. 161). Derby now definitely joined his uncle Gloucester, Richard Fitzalan, earl of Arundel (1346–1397) [q. v.], and Thomas Beauchamp, earl of Warwick [q. v.]. Thomas Mowbray [q. v.], earl of Nottingham and earl-marshal, followed his example. On 12 Dec. 1387 the five met at Huntingdon. The hesitation of the two new confederates alone prevented the adoption of Arundel's plan to capture and depose the king (Rot. Parl. iii. 376; Monk of Evesham, p. 137). Derby was first in the field in the hostilities that ensued. On 20 Dec. he blocked the way of the Duke of Ireland, who was advancing with a wild horde of Welsh and Cheshire men, by occupying Radcot Bridge in Oxfordshire. The duke took flight (Knighton, c. 2703–4). Henry and Warwick led the van of the host of the five lords which marched through Oxford (Adam of Usk, p. 5), reached London on 26 Dec., and camped in the fields at Clerkenwell. The citizens gladly opened their gates, and Henry was ever afterwards their hero. Richard was forced to give audience in the Tower to the five lords, and to concede their demands against the favourites. Henry could not resist the unworthy triumph of showing the king the vast throng beneath
