such a scheme was ‘neither feasible, safe, nor honourable for him.’ She pressed for his return to Holland, saying, ‘Though it be a great honour and happiness to him to wait upon his uncle, yet, his youth considered, he will be better employed to see the wars’ (Green, v. 540; Cal. State Papers, Dom. 1636–7 p. 559, 1637 p. 82). In July 1637 Charles dismissed Rupert, granting him a monthly pension of eight hundred crowns.
During his stay in England he had earned the good opinion of the king and the court. ‘I have observed him,’ wrote Sir Thomas Roe [q. v.] to the queen of Bohemia, ‘of a rare condition, full of spirit and action, full of observation and judgment. Certainly he will réussir un grand homme, for whatsoever he wills he wills vehemently: so that to what he bends he will be in it excellent. … His majesty takes great pleasure in his unrestfulness, for he is never idle, and in his sports serious, in his conversation retired, but sharp and witty when occasion provokes him.’ In a second letter he added: ‘It is an infinite pity he is not employed according to his genius, for whatsoever he undertakes he doth it vigorously and seriously. His nature is active and spriteful, and may be compared to steel, which is the commanding metal if it be rightly tempered and disposed’ (ib. 1636–7 p. 71, 1637 p. xxvi).
In the autumn of 1637 Rupert took part in the siege of Breda. In 1638 the elector palatine raised a small army and invaded Westphalia, accompanied by Rupert. On 17 Oct. they were defeated by the Austrian general Hatzfeld at Vlotho on the banks of the Weser, and Rupert, after performing prodigies of valour, was taken prisoner (Warburton, i. 83; Charvériat, Histoire de la Guerre de Trente Ans, ii. 406). It was at first reported that Rupert was killed, and the queen of Bohemia was inclined to wish it were true. ‘Rupert's taking is all. I confess in my passion I did rather wish him killed. I pray God I have not more cause to wish it before he be gotten out.’ She feared that her son might be perverted to catholicism by the influences which would be brought to bear upon him, although he assured her that ‘neither good usage nor ill should ever make him change his religion or party.’ ‘I know,’ she wrote, ‘his disposition is good, and he never did disobey me, though to others he was stubborn and wilful. I hope he will continue so, yet I am born to so much affliction as I dare not be confident of it’ (Green, v. 560). Rupert was imprisoned at Linz, where he remained for the next three years. His captivity, which was at times very strict, was alleviated by the study of drawing and painting, and by a love affair with the governor's daughter. The intervention of the Archduke Leopold procured him greater indulgence; he was allowed to shoot, to play tennis, and finally to hunt. In 1641 Sir Thomas Roe succeeded in negotiating his unconditional release, but Rupert appears to have promised not to bear arms against the emperor in future (Warburton, i. 91–105; Cal. State Papers, Dom. 1641–3, p. 140). He rejoined his mother at The Hague on 10 Dec. 1641, and then set out to thank Charles I for procuring his freedom. He arrived in England about the middle of February, but returned at once in order to escort Henrietta Maria to Holland (ib. pp. 198, 288, 294, 372).
The outbreak of the civil war opened a career for Rupert, and in July 1642 he landed at Tynemouth and joined Charles at Nottingham (Warburton, i. 462). The king made him general of the horse, and, while instructing him to consult the council of war, authorised him to act independently of that body if he thought fit (Instructions, Catalogue of Rupert MSS. No. 107). His commission exempted him from the command of the Earl of Lindsey, the general of the king's army, and gave rise to faction among the officers and to dissensions between the military and civil advisers of the king (Clarendon, Rebellion, vi. 78, 90). Rupert refused to receive the king's orders through Lord Falkland, the secretary of state. Hyde, who was personally obnoxious to the prince as being the leader of the peace party, complains of his ignorance of the government and manners of the kingdom, and his rough and unpolished nature. His contempt of the king's council was, according to the same authority, the cause of the misfortunes of himself and the kingdom (ib. vi. 21, 78, vii. 289; Warburton, i. 368).
At the beginning of the war, however, Rupert's energy and activity were of the greatest value to the king's cause. His example inspired his followers: ‘he put that spirit into the king's army that all men seemed resolved’ (Memoirs of Sir Philip Warwick, p. 227). With a small body of cavalry, which numbered at first only eight hundred horse, he traversed the midland counties, raising men and money for Charles. ‘Prince Rupert,’ writes a parliamentary historian, ‘like a perpetual motion, was in a short time heard of at many places at a great distance’ (May, Long Parliament, ed. 1854, p. 249). On 23 Sept. 1642 he gained the first victory of the war, defeating at Worcester a body of Essex's cavalry, commanded by Nathaniel Fiennes [q.v.] (Clarendon, vi. 44; Rushworth, v. 24). A month later at Edgehill Rupert's plan of
