As Monte Cristo had given Sir Redvers Buller Hlangwani, so Hlangwani rendered the whole of the western section (the eastern section was already in our hands) of the Colenso position untenable by the enemy, and they, finding themselves commanded and enfiladed, forthwith evacuated it. On the 19th General Buller made good his position on Green Hill, occupied Hlangwani with Barton's Brigade, built or improved his roads and communications from Hussar Hill across the Gomba Valley, and brought up his heavy guns. The Boers, who were mostly on the other side of the river, resisted stubbornly with artillery, with their Vickers-Maxim guns and the fire of skirmishers, so that we suffered some slight loss, but could not be said to have wasted the day. On the 20th the south side of the Tugela was entirely cleared of the enemy, who retired across the bridge they had built, and, moreover, a heavy battery was established on the spurs of Hlangwani to drive them out of Colenso. In the afternoon Hart's Brigade advanced from Chieveley, and his leading-battalion, under Major Stuart-Wortley, occupied Colenso village without any resistance.
The question now arose—Where should the river be crossed? Sir Redvers Buller possessed the whole of the Hlangwani plateau, which, as the reader may perceive by looking at the map opposite p. 448, fills up the re-entrant angle made opposite Pieters by the Tugela after it leaves Colenso. From this Hlangwani plateau he could either cross the river where it ran north and south or where it ran east and west. Sir Redvers Buller determined to cross the former reach beyond Colenso village. To do this he had to let go his hold on the Monte Cristo ridge and resign all the advantages which its possession had given him, and had besides to descend into the low ground, where his army must be cramped between the high hills on its left and the river on its right.
There was, of course, something to be said for the other plan, which was advocated strongly by Sir Charles Warren. The crossing, it was urged, was absolutely safe, being commanded on all sides by our guns, and the enemy could make no opposition except with artillery. Moreover, the army would get on its line of railway and could 'advance along the railroad.' This last was a purely imaginary advantage, to be sure, because the railway had no rolling-stock, and was disconnected from the rest of the line by the destruction of the Tugela bridge. But what weighed with the Commander-in-Chief much more than the representations of his lieutenant was the accumulating evidence that the enemy were in full retreat. The Intelligence reports all pointed to this situation. Boers had ridden off in all directions. Waggons were seen trekking along every road to the north and west. The camps between us and Ladysmith began to break up. Everyone said, 'This is the result of Lord Roberts's advance: the Boers find themselves now too weak to hold us off. They have raised the siege.'
But this conclusion proved false in the sense that it was premature. Undoubtedly the Boers had been reduced in strength by about 5,000 men, who had been sent into the Free State for its defence. Until the Monte Cristo ridge was lost to them they deemed themselves quite strong enough to maintain the siege. When, however, this position was captured, the situation was revolutionised. They saw that we had found their flank, and thoroughly appreciated the significance and value of the long high wedge of ground, which cut right across the left of their positions, and seemed to stretch away almost to Bulwana Mountain. They knew perfectly well that if we advanced by our right along the line of this ridge, which they called 'the Bush Kop,' supporting ourselves by it as a man might rest his hand on a balustrade, we could turn their Pieters position just as we had already turned their entrenchments at Colenso.
Therein lay the true reason of their retirement, and in attributing it either to Lord Roberts's operations or to the beating we had given them on the 18th we made a mistake, which was not repaired until much blood had been shed.
I draw a rough diagram to assist the reader who will take the trouble to study the map. It is only drawn from memory, and its object is to show how completely the Monte Cristo ridge turned both the line of entrenchments through Colenso and that before Pieters. But no diagrams, however exaggerated, would convince so well as would the actual ground.
Plan of the Colenso Position
In the belief, however, that the enemy were in retreat the General resolved to cross the river at A by a pontoon bridge and follow the railway line. On the 21st, therefore, he moved his army westward across the Hlangwani plateau, threw his bridge, and during the afternoon passed his two leading infantry brigades over it. As soon as the Boers perceived that he had chosen this line of advance their hopes revived. 'Oh,' we may imagine them saying, 'if you propose to go that way, things are not so bad after all.' So they returned to the number of about nine thousand burghers, and manned the trenches of the Pieters position, with the result that Wynne's Lancashire Brigade, which was the first to cross, soon found itself engaged in a sharp action among the low-kopjes, and suffered a hundred and fifty casualties, including its General, before dark. Musketry fire was continuous throughout the night. The 1st Cavalry Brigade had been brought in from Springfield on the 20th, and on the morning of the 22nd both the Regular and Irregular Cavalry were to have crossed the river. We accordingly marched from our camp at the neck between Cingolo and Monte Cristo and met the 1st Cavalry Brigade, which had come from Chievejey, at the pontoon bridge. A brisk action was crackling away beyond the river, and it looked as if the ground scarcely admitted of our intervention. Indeed, we had hardly arrived when a Staff Officer came up, and brought us orders to camp near Hlangwani Hill, as we should not cross that day.