In 1889, his elder brother Fred (Edward Frederick Bulmer), returned from King’s College, Cambridge, to join Percy in his new venture, having rejected an offer of a post as tutor to the children of the King of Siam. With a £1,760 loan from their father, the brothers bought an 8 acre field just outside the city and built their first cider mill in Ryelands Street, Hereford.

After buying an orchard in Co. Tipperary, William Magner began to produce his own Irish cider in 1935.

After the war in 1946, H.P. Bulmer purchased the remaining 50% of the Bulmers business in the Republic of Ireland, changing the name to Bulmers Ltd Clonmel. H.P. Bulmer maintained international rights to the Bulmers trade mark, ensuring exports were distributed via the parent company rather than directly exported from Ireland.

In 1964, H.P. Bulmer was forced to sell Bulmers Ltd Clonmel to Guinness and Allied Breweries, the parent company of Showerings. The company name was changed to Showerings (Ireland) Ltd.

In 1968, Guinness merged Cantrell & Cochrane with the Irish soft drinks operations of Allied Breweries (later Allied Domecq) to form C&C.

Magners was first sold in the United Kingdom in late 1999 when the brand was launched in Northern Ireland.