Konstantin Romanovich of Ryazan

Konstantin Romanovich (died 1306) was the youngest son of Grand Prince Roman Olgovich of Ryazan and ruled Ryazan from 1299. In autumn 1301 Prince Daniil Alexandrovich of Moscow invaded, defeated a Tatar force Konstantin had hired, and captured him through a ruse, reportedly the treachery of his own boyars.

Daniil planned to free him after peace but died in 1303, and his successor Yury Danilovich ordered Konstantin killed in 1306. His son Vasily succeeded in Ryazan.