The United Kingdom's preparations were largely guided by its experience in the Second Boer War of 1899–1902. The British purchased the field guns that the Boers had used against them, and used these as prototypes for their own weapons. The British also modeled their howitzers after those used by the Boers. Some British designs were used by the United States. The British also supplied guns to Australia and New Zealand.^[7] Despite the long tradition of British naval heavy artillery developments, the British Empire did not have heavy field artillery before World War I, which disadvantaged the British infantry in the first years of the war.