His mother died in 1770 and Mary Parker, the governess hired to look after him, became his father's mistress and bore Erasmus two illegitimate daughters.

In 1783, Darwin began his studies of medicine at the University of Edinburgh, where he apparently took lodgings with the chemistry professor Joseph Black.

[3][4] With small inheritances from his mother and an aunt, Darwin invested in housing, buying the freehold of several buildings in Shrewsbury and getting income from rents.

He became a major stockholder in the Trent and Mersey Canal, and an investor in the London to Holyhead road built by Thomas Telford as another part of the infrastructure of the Industrial Revolution.

Robert Darwin purchased land overlooking the River Severn and had a large red-brick house built there around 1800 which was named The Mount, where all their other children were born.

He required his coachman to test the floorboards of houses he was visiting, and had to have special stone steps made for him to enter his carriage.

Robert Darwin provided the first empirical evidence that small eye movements are made even when people attempt to keep them fixed.