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The name Shell is linked to The "Shell" Transport and Trading Company. In 1833, the founder's father, Marcus Samuel, founded an import business to sell seashells to London collectors. When collecting seashell specimens in the Caspian Sea area in 1892, the younger Samuel realised there was potential in exporting lamp oil from the region and commissioned the world's first purpose-built oil tanker, the Murex (Latin for a type of snail shell), to enter this market; by 1907 the company had a fleet. Although for several decades the company had a refinery at Shell Haven on the Thames, there is no evidence of this having provided the name.

The company operated a refinery on what river for several decades?
Thames