The ships arrived in mid-October, a few days after the Second Boer War began. "Terrible"s captain, Percy Scott, then improvised field carriages for some naval guns to satisfy a request for more long-range artillery. "Powerful"s captain, the Hon. Hedworth Lambton led a naval brigade and some of Percy's guns to reinforce the garrison of Ladysmith in late November. "Terrible" contributed a naval brigade and guns of her own during the Relief of Ladysmith in December 1899–March 1900. The performance of the gun crews from both ships inspired the RN's field gun competition. The ships continued on their respective voyages after Ladysmith was succored in March, "Powerful" to much acclaim in England and "Terrible" to China where her crew and guns helped to suppress the Boxer Rebellion a few months later. They were part of the relief force that reached the foreign quarter of Tientsin in June as well as the expedition that defeated the Chinese forces in the city of Tientsin in mid-July. And then they participated in the second relief expedition to Peking in August before returning to the ship in September. Afterwards Scott devoted himself and his crew to gunnery training and later had his methods adopted by the entire Royal Navy.