The originator of the Jacob’s brand name was the small biscuit bakery, W & R Jacob, founded in 1885 in Bridge Street, Waterford, Ireland by William Beale Jacob and his brother Robert. It later moved to Bishop Street in Dublin, Ireland, with a factory in Peter’s Row. A factory in Liverpool was opened in 1914. The Bishop Street premises was one of several prominent Dublin buildings occupied by rebels during the Easter Rising of 1916. In the 1922 a separate English company was formed, W & R Jacob (L’pool) Ltd.  The two branches separated, with the Dublin branch retaining the W & R Jacob name while the Liverpool branch was renamed Jacob’s Bakery Ltd. In the 1970s, W & R Jacob in Dublin merged with Boland’s Biscuits to form Irish Biscuits Ltd. and moved to Tallaght, Ireland. The Liverpool factory joined Associated Biscuits in 1960, which was purchased by Nabisco in 1982.

Info gleaned from Wikipedia