There is a fascinating legend that Alexander I faked his own death and "retired" from life under another name.
At one point a man named Fedor Kuzmich appeared in Tomsk and local residents suspected that this might well be Tsar Alexander himself. In 1864 Kuzmich was lying on his death bed, his last words being, "God only knows my real name!"
Allegendly, in 1865, Tsar Nicholas attempted to quell the rumors about his brother and had his casket opened. Rumors soon spread about the casket being empty. Then in 1926, over one hundred years after Alexander's death his casket was opened again and was officially declared empty. To this day, supposedly no one really knows where he lays buried.