Just three years earlier, Charles the I was executed. Everything was turned on its head, and something big was afoot. Culpeper deduced that the eclipse heralded the second coming, so he wrote a pamphlet explaining the eclipse and issuing his dire warnings. Among his many predictions were a great plague and a fire. He got that right, but he was a little quick on the trigger. In 1665 London was hit by the Black Plague, and the following year, ravaged by the Great Fire.
As a physician, Culpeper was ready to help. He died in 1654, but he left behind a truly bizarre cure for the plague that you can read about here.
To read about the eclipse and its threats, ask for Nicholas Culpeper's Catastrophe magnatum: or, The Fall of the Monarchie. A Caveat to Magistrates, Deduced from the Eclipse of the Sunne, March 29 1652 (London: T. Vere and Nathe, 1652).