You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
IOTL, Peter II of Russia was the grandson of Peter the Great, but the famous Tsar also had another Peter . Of the six sons Peter the Great had with Catherine I, only one lived for more than a year - Grand Duke Pyotr Petrovich. But sadly he died in 1719. (http://genealogy.euweb.cz/russia/romanov2.html#P1)
IOTL, Peter the Great died without naming an heir, and he took little to no interest in OTL Peter II because the boy reminded him of his own son, Alexei. What if Peter's son by Catherine survived? He would be about the same age as Alexei's son, and I'd assume he would be more in the camp of 'new men' like his mother and Alexander Menshikov. I'd guess the latter would try and betroth his daughter to Catherine's son instead of Alexei's son.
Would Catherine still become Empress or just part of a regency council ruling on *Peter II's behalf? One possible outcome could be a civil war - a Russian War of the Two Peters - between the reformers supporting Catherine's son and the conservatives supporting Alexei's son.