Still persevering he moved on to the Modder, where he was seriously opposed by De la Rey and P. A.
It was a long and wearing fight, in which the British lost 485 killed and wounded, and what was more serious, Lord Methuen (himself wounded) found that his force had exhausted its forward momentum, and that he would have to collect supplies and reinforcements on the Modder before fighting his next battle.
On the following day Lord Methuen delivered an attack upon Cronje's position between the Upper Modder river and the Kimberley road, a line of kopjes called Spytfontein and Magersfontein.
On the 3rd of February he ordered a demonstration against the right of the Boer position at Spytfontein-Magersfontein to cover the withdrawal of General French and the cavalry from before Colesberg, and the concentration of his army at Modder River, disregarding another set-back in Natal to Sir Redvers Buller, who had against his advice made a third attempt to relieve Ladysmith on the 5th of February, and failed to make good the purchase which he secured across the Tugela.
Lord Roberts's plan was first to concentrate to his left, taking every measure to induce the Boers to believe that the original scheme of invasion by the centre would now be resumed, and in this purpose he succeeded so well that his field army with the necessary transport for a cross-country march was assembled between the Orange and the Modder without serious mishap. Cronje at the new centre of gravity was not reinforced, all available Boers drawing down towards Colesberg.
The concentration effected, Cronje still believed that the relief of Kimberley was the object of the gathering behind Modder River, and therefore held on to his Magersfontein kopje.
Skirmishing with De Wet in the first stages of their ride, the cavalry brigades crossed the Modder at Klip Drift on the 13th.
The chief tributaries of the Vaal (q.v.) wholly or partly within the province are, going from east to west, the Klip (this stream from near its source to its confluence with the Vaal divides the Free State from the Transvaal), the Wilge, Rhenoster, Vet, Modder and Reit.
The valleys of the Modder, Reit and the lower Caledon contain rich alluvial deposits.
On the 22nd of January Kruger met Warren at the Modder river, and endeavoured to stop him from proceeding farther, saying that he would be responsible for keeping order in the country.
He opposed the advance of the British division under Lord Methuen, and fought, though without success, three general actions at Belmont, Graspan and Modder River.
Among other Dutch words frequently used in place-names may be instanced: rhenoster (rhinoceros) olifant (elephant), mooi (pretty), modder (mud), klip (cliff), berg (mountain), burg or stad (town), zwart (black), klein (little), groote (great), breede (broad), nieuw (new), zuur (sour), bokke (buck).