After serving during World War II, he began his career at the Post and Telegraph Department. He was a member of the workers' union in the department and rose to become President of the department's Ex-Servicemen's Union in 1948. In 1952, he became President of the Post and Telegraph's Clerical and Workers Allied Union. bringing in
First Bank of Boston (later
Bank of Boston) alongside other indigenous investors. The bank was setup after his sudden death with the technical assistance and shareholding of
Bank of Boston and Boston Overseas Financial Corporation (subsequently merged with
Bank of America). Fajemirokun was a pioneer in the Nigerian maritime industry and was the first indigenous company to own an interest in a
shipping line. He established Henry Stephens Shipping Company and the Nigeria Shipping Company with two lines: Nigeria-Far East Line and the Nigeria-South America Line and acquired three drybulk ships. The Nigeria- South America Line provided liner services between Brazil and the Nigerian Far East Line provided liner services to Japan and the Far East. Fajemirokun also ventured into
commodity brokerage and in 1969 he bought and held a seat on the
London Stock Exchange. Fajemirokun's company Henry Stephens was a pioneer in Nigerian Oil industry as the first indigenous private oil company to get an offshore exploration license in the country's first ever offshore licensing round of oil prospecting licenses (OPL) in 1970. Bidding was opened between 26 February and 18 March on about 7000 square miles of the continental shelf. Twenty seven blocks were offered composed of areas relinquished according to leasing regulations 30 November 1968 plus additional deeper water acreage up to the 200 fathom line on the outer shelf. A total of 106 bids from over 30 oil companies or groups were made for these continental shelf OPLs. In July, Newcomers to Nigeria were offered blocks. Only 15 blocks were offered covering only half of the open area. The remaining blocks said to be the most prospective, were reserved for the proposed national oil company
Nigerian National Oil Corporation (NNOC) which was established officially in 1972 .Other winners of the licensing round were Deminex a German Consortium,
Occidental Petroleum,
Japan Petroleum Company and
Monsanto. The Group acquired the sole distributorship for Rank Xerox (now
Xerox), forming a joint venture with the Anglo-American company
Rank Xerox (itself a joint venture between
Rank Organisation of the United Kingdom and the
Xerox Corporation of the United States of America). Fajemirokun was a co-founder and played a key role in developing and promoting ECOWAS Bank what was to become Ecobank Transnational (ETI), however he died before its launch was finalized. As an active investor he became a major shareholder in leading companies in Nigeria and abroad. He was denied the opportunity to acquire the
Daily Times of Nigeria from the British
International Publishing Corporation, (
IPC) known as the "
Daily Mirror Group" who owned the title by the Obasanjo
junta. Henry Stephens also was a core investor in
Johnson Wax and acquired stakes
Fan Milk and two notable construction companies. Fajemirokun was also a director of First Bank Nigeria Limited, director Nigeria Krafts Bags Limited, non-executive director Nigerian Diversified Investments, director Nigeria Sewing Machine Manufacturing Company Limited. He was Chairman of the Lagos State Tourism Advisory Committee. == Philanthropy and awards ==