1900 – 1950 Joining forces, Unilever comes to life

In the year that war breaks out, companies controlled by Lever Brothers are making about 135 000 tons of soap a year. For employees drafted to war, Lever Brothers agreed to re-employ them on their return and give allowances to their dependants whilst they were away.

In 1917, Jurgens and Van den Bergh establish factories in England, with one in Purfleet, Essex, which is still manufacturing margarine today. The factory is extended in 1957 and again in 1971, and by 1959 there are 1,000 workers employed there. They make Stork Margarine, processed cheese and soft drinks. In more recent years, the Purfleet factory has expanded to make some of Unilever's best-known brands such as Flora, Bertolli and Olivio and is reputed to be the largest margarine factory in the world.

The post-war boom is in decline and during the 1920s the margarine market suffers as butter becomes more affordable. By the end of the 1920s, Jurgens owns margarine factories in Scotland, Ireland and England and Lever Brothers controls 60% of the output of UK soap manufacturing. Before the decade is out, alliances reach their ultimate conclusion and the official history of Unilever begins.

Lever Brothers launches its Clean Hands Campaign. As part of its child health policy, it encourages the habits of personal cleanliness among primary school children, educating them about dirt and germs and teaching them how to wash their hands properly. Children are encouraged to complete a 'Clean Hands Chart' which is marked each time they wash their hands 'Before Breakfast', 'Before Dinner' and 'After school' for each day of the week.

Margarine businesses Jurgens and Van den Bergh, Jbusinesses, Centra and Schicht join forces to create Margarine Unie - the Margarine Union. The union quickly gains new members, creating a large group of European businesses involved in the production of almost all goods created from oils and fats. In 1928, Margarine Unie acquires the French-Dutch Calvé-Delft group with factories in the Netherlands, France, Belgium and Czechoslovakia. The following year the Union also acquires the firm Hartog's.

The 1930s is a tough decade - it starts with the Great Depression and ends with a new world war. But despite the recession the business continues to expand, partly through the development of new products in its established markets, and partly by acquiring companies to take it into emerging categories like frozen and convenience foods. Soap production also moves further from hard soaps to flakes and powders designed to make lighter work of household cleaning. This leads to expansion in the soap market.

On 2 September 1929, Margarine Unie and Lever Brothers sign an agreement to create Unilever. The businesses initially aim to negotiate an arrangement to keep out of each other's principal interests of soap and margarine production, but ultimately decide on an amalgamation instead. Described in The Economist as “one of the biggest industrial amalgamations in European history”, Unilever is officially established on 1 January 1930. However, the year also sees Procter & Gamble enter the UK market, becoming one of Unilever's largest rivals.