Despite an active working and business life, Russell was prominent in the raising of a militia unit of the New Zealand Volunteer Force following the outbreak of the Boer War in 1899. He commanded the unit, the Wellington (East Coast) Mounted Rifles Regiment, which by 1901 numbered about 900 men. Most of his volunteers were young farm workers who provided their own horses and saddles, while the Defence Department provided rifles and other equipment. Russell set about training his unit, an experience that he greatly enjoyed and which rekindled his interest in the military. However, his work and family commitments kept him from volunteering for active service in South Africa.