The Muscovite rebellion, also known as the First Ruscian Civil War, was a war in the 1700s. The decline of Rusica following the war is often attributed to this, as is the Second Ruscian Civil war, which is what is generally considered the true end of Rusican Superpowerdom.
Following an absolutely catastrophic series of wars with Brandenburg and Angland, Ruscia was in ruins. Much of the Novgorod-Moscow area was desolate; both cities had been sacked multiple times, including the infamous Great Sack of Moscow, when 100,000 Brandenburgish and Anglish troops marched into Muscovy and burnt it - and most of its inhabitants - to the ground, then marched back to the Baltic Sea, destroying Tver, Rostov, and Novgorod along the way. The much richer provinces of Muscovy, Ryazan, and Novgorod were tired of throwing away their soldiers into wars which they neither started nor wished to continue. Meanwhile, the Western provinces of Kiev and Lithuania were relatively untouched by the war, despite being the seat of the Ruscian government. After the last, devastating war in 1714 left Ruscia with no allies - Scandinavia had been ripped apart by Angland, while Poland had been all but annexed by Brandenburg - and with hundreds of thousands of Ruscians dead, the Tsardom nearly fell apart. Due to the actions of Evegni I, Grand Duke of Novgorod, the richer Eastern provinces did not leave the Tsardom. But