He was educated at Plumtree School.
Soon after leaving school he joined the army in the 1939-45 war serving with the Rhodesia Regiment and the Ring’s African Rifles, rising to be a captain. On demobilisation he qualified as attorney, notary and conveyancer. He became MP for Jameson and entered the government on December 17, 1962, as Minister of Internal Affairs, Local Government and African Education. He visited Canada and the USA in September 1963 to test support for independence moves but resigned in April 1964 when Smith ousted Winston Field. He stayed as a backbencher until May elections in 1965 when he was returned unopposed and appointed Minister of Immigration, Tourism and Information by Premier Smith on May 21. 1965.
He succeeded Lord Graham as Minister of External Affairs and Defence on September 13, 1968. He was alleged to have been marked down for assassination at a fee of £50 during the murder plot case against the Rev. Ndabaningi Sithole, the ZANU leader, in February 1969. On defence matters he developed close co-operation with South Africa and Portugal and was consequently embarrassed by Premier Ian Smith’s decision to close the border with Zambia on January 9, 1973, without any consultation with these defence partners.
Under the slogan “Secrecy Saves Lives” he supervised censorship in the crucial first phase of UDI. His censors were instructed to delete any reference to Sir Humphrey Gibbs as Governor in all radio and Press reports of House of Commons speeches in an attempt to switch loyalties to Clifford Dupont as Officer Administering the Government. During the visit of British Minister Herbert Bowden in September 1966 Howman’s censorship resulted in 70 inches of blank space on one day’s issue of the “Rhodesia Herald”.
When he made bitter accusations of “slanted reporting" he was taken to court. The verdict on July 20, 1967, required Howman to pay damages and costs to two editors and their publishers for defamation. As Minister for Immigration he deported nine lecturers from Salisbury University on August 17, 1966, with allegations that they had been “actively engaged in the propagation of subversion”. His critics accused him of always “seeing Reds under the bed” and he continually campaigned against Communism with the warning: “The real menace facing the world today is Red China.”
Close associate of Premier Ian Smith, who put him in charge of censorship after UDI. His ruthlessness often left Rhodesia’s newspapers with large blank spaces. He was known as Smith’s gagman for his GAG—Guard Against Gossip—campaign. As a hardliner he kept a watching brief for the party’s right wingers at the negotiations Premier Smith had with British ministers aboard HMS Tiger in December 1966 and HMS Fearless in October 1968.