In 1835, Dublin shipowner Captain Richard Bourne joined the business, and the three men chartered the William Fawcett and started a regular steamer service between London and Spain and Portugal – the Iberian Peninsula – using the name Peninsular Steam Navigation Company, with services to Vigo, Oporto, Lisbon and Cádiz.

As the Peninsular and Oriental Steam Navigation Company was incorporated in 1840 by a royal charter its name therefore included neither "plc" nor "Limited".

At the height of the Carlist Wars the British lent their support to the legitimate heirs of Spain and Portugal and all three P&O founders played their part, from gun running to chartering steamers.

[3] The company later introduced round trips to destinations such as Alexandria and Constantinople and underwent rapid expansion in the later half of the 19th century, with its ships becoming larger and more luxurious.

[6] Mail contracts were the basis of P&O's prosperity until the Second World War, but the company also continued to become a major commercial shipping line and passenger liner operator.

At this time it established a commercial relationship with Spinney's of Haifa, that developed into a major regional high-end grocery store chain, which eventually provided shipping services access to much of the Middle East.

After 1945, the passenger market declined to India, but boomed to Australia with the advent of paid-passages for literate and healthy European immigrants known as Ten Pound Poms.

[7] P&O built 15 large passenger liners, including Himalaya, Chusan, Arcadia, and Iberia, culminating in Oriana and Canberra, which were an unprecedented speed and size.

In 1969, British and Commonwealth Shipping, Furness Withy, P&O and The Ocean Steamship Company established Overseas Containers Limited (OCL) to exploit containerisation.

On 6 March 1987, the roll on/roll off ferry, Herald of Free Enterprise, capsized off the coast of Zeebrugge with 80 crew and 459 passengers aboard.

Some records state that original staff members partially diverged to form Paeteco Imports and Exports in 2005, a small, privately held international subsidiary of Jcorp.

[16] Despite speculation that it would make a higher bid, PSA withdrew, and in February 2006 shareholders voted in favour of the offer from Dubai.

When the merger was approved by the US government in February 2006, the Bush Administration came under fire from critics who questioned the decision to allow an Arab-owned company to oversee US ports.

The move placed the leasehold interests of P&O in New York City, Newark, Baltimore, Miami, New Orleans, and Philadelphia under the control of Dubai Ports World.

David Osler, Industrial Shipping Editor of Lloyd's List said that US security procedures and overall port control would not be affected by the transaction.

[18] Several US states sought ways to block the move, citing security concerns as well as the possibility of losing related leases of foreign ports.

AIG GIG was an experienced infrastructure investor globally, having also recently acquired the London City Airport.

[22] On 16 December 2006 P&O Dover (Holdings) Limited, a subsidiary of P&O and DP World sold its shares Phase 1 (22.5%) and Phase 2 (owned indirectly 22.5% shares), a port of Shenzhen, People's Republic of China, to a joint venture company of China Merchants Holdings (International) and Modern Terminals Limited (MTL), for which MTL bore the whole cost.