Hartley’s was a grocers founded by Sir William Pickles Hartley near Pendle, Lancashire. In 1871 a supplier failed to deliver a consignment of jam, so William made his own and packaged it in his own design earthenware pots. It sold well and in 1874 the business moved to Bootle, near Liverpool and marmalade and jelly was also produced. In 1884 the business was incorporated as William Hartley & Sons Limited and in 1886 it moved to Aintree, Liverpool where a new factory was built.
Info gleaned from Wikipedia