Promasidor was founded in 1979 by Robert Rose, who moved from the UK to Zimbabwe in 1957 to pursue his African dream. As Chairman of Allied Lyons Africa for over 20 years, he travelled extensively throughout Africa and acquired a unique and in-depth knowledge of the food industry across the continent. In particular, he realised the lack of availability of a highly nutritious product that the developed world takes for granted: milk. He realised that, with the rapid advance of milk powder manufacturing technology, there was an excellent opportunity to provide milk powder in small portions that could be packaged in flexible sachets. It discovered that removing animal fat from milk and replacing it with vegetable fat allowed for a longer shelf life. This meant that powdered milk could be distributed across the vast African continent for the first time, providing affordable access to milk for everyone in Africa.

Passionate belief in this vision fuelled the pioneering concept of selling powdered milk packaged in small sachets. Promasidor began selling the Cowbell brand in the Democratic Republic of Congo (then Zaire) in 1979. Today, Cowbell is sold in most countries on the African continent.