The Clan Line was founded in 1877 in Liverpool as C. W. Cayzer & Company, trading from the UK to India. The company became Cayzer, Irvine & Company in 1878 when Captain William Irvine joined the firm. In 1881 the Clan Line Association of Steamers was formed and, with an influential Glasgow businessman joining the firm, the company was moved to Glasgow. Clan Line head office was established at 109 Hope Street, Glasgow. New ships were built and managed for the Association by Cayzer Irvine, with Cayzer retaining ownership of the original six Clan ships.

In 1890 the name of the company became The Clan Line of Steamers Limited with Cayzer holding majority interest. The company purchased the Persian Gulf Steam Ship Company in 1894 and their fleet of four ships. Fare at this time from Liverpool to Madras or Calcutta was £45 first class and £30 second class.

The company became Cayzer, Irvine & Company, Limited, in 1907 and in 1918 the assets of the Scottish Shire Line were acquired. The same year the Houston Line was taken over together with the British and South American Steam Navigation Company, but all three of these companies retained their own system of ship naming, colours and liveries.

In 1956 a merger took place between the Clan and Union-Castle groups (including King Line and Bullard King & Company) to form the British & Commonwealth Shipping Limited and many transfers between component companies within the group took place after this date.

The South African based subsidiary Springbok Shipping Company was formed in 1959 to operate South African services and several Clan ships were transferred to this new company, which in 1961 became part of Safmarine. Hector Whaling came into the group in 1962.

In 1981, the Clan Line ceased trading but Cayzer Irvine managed ships until 1987, including the Stirling Universal for Union-Castle from 1981-1987. When Cayzer sold the British & Commonwealth Shipping Company Cayzer Irvine changed its name to C I Shipping, Limited and managed the Stirling Universal for a further year prior to its sale to Iran in 1988.

By 1986 British & Commonwealth had disposed of their last ship - having fully diversified into other fields of activity such as financial services, aviation, hotels, commodity trading and office equipment.

The British & Commonweath Group was a subsidiary of Caledonia Investments PLC (www.caledonia.com), the Cayzer family holding company. In October 1987 Caledonia sold their holding in the British & Commonwealth Group. In 1989 British & Commonwealth Group acquired Atlantic Computers, an apparently successful company. However this proved to be a disastrous move for the Group as Atlantic Computers financial outlook proved to be highly precarious and they had done some creative accounting to make their company appear highly successful. It was this acquisition of Atlantic Computers that precipitated the later collapse and liquidation of British & Commonwealth Group in 1990 with debts of over £1.5 billion.