Today is the anniversary of the disaster of Naseby in 1645, which was the key in a series of events which ultimately led to the Royalist defeat. The Companion to British History (2008 Edition), whose author was a great admirer of Prince Rupert, but not of Charles I, summarises the events leading up to the battle as follows:
Rupert and the more sensible courtiers saw that Charles still had enough to save something by a negotiated peace but not enough to win, but the King still hoped for too much from Ireland (where Glamorgan was negotiating on the basis of a secret treaty while Ormonde was attempting an open one) and was buoyed up by Montrose’s further exploits. On 4 Apr. he had raided Dundee.
The King was adamant and Rupert advised a northern campaign which could lend help to Montrose. Cromwell, however, struck from London northwards of Oxford on 23 Apr. while Fairfax marched towards Dorset. The King’s forces were now to concentrate for the northern campaign but his commanders were a quarrelsome lot; Rupert detached Goring to the West to get rid of him; and to hold Fairfax he himself marched for the north. The Committee of Both Kingdoms ordered Fairfax to leave the West and make for the threatened Midlands; the parliamentary siege of Chester was abandoned. Thereupon Rupert and the King stormed Leicester, having first recalled Goring. Goring, however, disputed his orders: he wanted a south western not a northern campaign. Fairfax and Cromwell’s forces were united on 2 June. On 14 June 1645 they together fought the King without Goring’s cavalry at Naseby. If Rupert’s advice had been followed the battle would not have been fought. The King lost his infantry, guns and secret correspondence and fled with the remnant of his cavalry to Wales.