Having inherited a fortune as a young man, he became a member of the gambling set associated with the Prince Regent and quickly lost his money.

He obtained a position as chaplain in the navy,[3] and was appointed to Colonel Collins's expedition which, after the failure of the Port Phillip settlement, landed on the site of Hobart on 19 February 1804.

On the other hand, he interested himself in two boys both under 18 years of age, who had been condemned to death, and succeeded in getting them reprieved at the foot of the gallows.

As the population grew and Knopwood's work increased, his salary was raised to £260[1] per annum in April 1817, but his health was not good.

Her daughter erected a tombstone in Rokeby churchyard to the memory of Knopwood which describes him as "a steady and affectionate friend, a man of strict integrity and active benevolence, ever ready to relieve the distress and ameliorate the conditions of the afflicted".