Sir Roderick Impey Murchison was a Scottish geographer notable for his geological surveys of Britain. In 1831, Murchison travelled to southern Wales to study fossils contained in Old Red Sandstone and greywacke formations, while his friend Adam Sedgwick visited the north of the country on a similar project. They hoped to combine their findings but in 1834, the pair parted ways without resolving that the fossils found in the lowest part of the strata studied by Murchison corresponded with those in the uppermost part of that studied by Sedgwick. The following year, Murchison published his findings, naming his system Silurian, the name coming from an indigenous British tribe, and in 1839, published the first edition of The Silurian System. In his book, Murchison argued that his strata contained the oldest known fossil-bearing rocks then known, laid down over 460 million years ago, and thus marked the origin of life on earth.

These statements brought Murchison into conflict with Sedgwick, who argued that the older strata he had observed (which he had named Cambrian) was that which contained the fossils, not the younger Silurian layers. Over the next four decades, Murchison continued to argue he was correct, appending new fossil discoveries to each subsequent edition of his work, gradually wearing down Sedgwick and ultimately ruining their friendship. The issue was not resolved until 1879, when a new system, the Ordovician, was proposed by Charles Lapworth to cover the rocks in question.