You gotta hand it to Russia's bigots. They are anything if not consistent.
Today, there are baseless Jewish rumors spread about the junta in charge: Vladimir Putin and Dmitry Medvedev. And that's not a new thing.
The titles might have changed, from Czar to Emperor to Chairman to General Secretary to President, but the bigots are always at it. He is in charge? He must have some Jew in him! Even Peter the Great, only the greatest ruler in the country's history, was not immune.
But here is the weird thing: in Peter's case, the rumors actually had a base. A very very very loose base, but one nonetheless.
Here's how: it all has to do with Mordka Kurbat, nicknamed Narysh, who came to Moscow from Crimea in the middle of the 15th century. Kurbat's grandson Isaac took the last name Naryshkin. In 1671, his descendant Natalya Naryshkina married czar Alexei, and gave birth to the man who would become Peter the Great. There are people out there who claim that Mordka was a Crimean Karaite, a Jewish sect. That, according to our math, would have made Peter 1/2048, or .05% Jewish.
So do the bigots get this one? We're not so sure. There is no clear confirmation that Mordka was a Karaite. There are diverging accounts of his arrival in Moscow, and the Slavic Encyclopedia calls him a Crimean Tatar, who weren't exactly Jewish. So until there is firmer evidence, we'll have to mark Peter as "Not a Jew".