Neither became independent,sovereign nations until the second half of the 19th century (1861 and 1871 respectively). Neither had a powerful navy when they became unified,so it took time to build up both a sufficiently large surface fleet and merchant marine to make imperial acquisitions overseas viable and defensible. A combination of these factors meant that,by the time both were ready and eager for imperial colonies in Africa,much of the continent (and certainly all the best bits) had long since been claimed by others.
