In April 1719 Peter I's second son, Tsarevich Peter Petrovich, dies at the age of three and a half
The French historian Adrien Richer, in his History of … the Russians, published in 1770, suggests that Peter “felt that the priests and adherents of the old faith would not fail to regard this unhappy accident as a just punishment for the death of Tsarevich Alexei.”
Tsarevich Alexei Petrovich had died in circumstances that have never been clarified, in confinement in the Peter and Paul Fortress, less than a year earlier, 303 days before the death of Tsarevich Peter Petrovich.
Of direct male heirs Peter was left only with his grandson, Peter II Alexeyevich
