"The difficulties of carrying on war in South Africa do not appear to be sufficiently appreciated by the British public. In an enemy's country we should know exactly how we stood; but out here we have not only to defeat the enemy on the northern frontier, but to maintain law and order within the colonial limits. Ostensibly, the Dependency is loyal, and no doubt a large number of its inhabitants are sincerely attached to the British rule and strongly opposed to Boer domination. On the other hand, a considerable section would prefer a republican form of government, and, influenced by ties of blood and association, side with the Orange Free State and the Transvaal. Even the public service at the Cape is not free from men whose sympathies with the enemy may lead them to divulge secrets and give valuable assistance to the Boer leaders in other ways." [Sidenote: The offensive campaign.] Bearing in mind that the offensive campaign dates, not from the expiry of the Boer ultimatum on October 11th, 1899, but from Lord Roberts's advance from Modder River Station on February 11th, 1900, the mere record of dates and events is sufficiently impressive. On February 12th the Free State border was crossed; on the 15th Kimberley was relieved, on the 27th Cronje's force surrendered at Paardeberg, on the 28th Ladysmith was relieved, and on March 13th Bloemfontein, the capital of the Free State, was occupied. The army again advanced early in May; Kroonstad was entered on the 12th; on May 24th, the Queen's birthday, the Free State was annexed; the Vaal was crossed on the 27th, Johannesburg was occupied on the 31st, and on June 5th the British flag was hoisted on the Raadzaal at Pretoria. In the meantime Mafeking had been relieved with absolute punctuality on May 17th.[197] On June 11th the Boers evacuated Laing's Nek and Majuba, and the Natal Field Force, under Buller, entered the Transvaal from the south-east. The next day Roberts defeated the Boers under Louis Botha at Diamond Hill. On July 30th Prinsloo and 4,000 burghers surrendered to Hunter; on August 27th the main Transvaal army, under Louis Botha, was again defeated at Dalmanutha, and on September 1st the Transvaal was annexed. On the 11th President Krüger fled the Transvaal; Komati Poort, the eastern frontier town on the railway line to Delagoa Bay, was entered on the 24th, and two days later railway communication was re-opened between Delagoa Bay and Pretoria. [Footnote 197: Lord Roberts had asked Col. Baden-Powell how long he could hold out at Mafeking, and then promised that the relief of the town should be effected within the required period.]