Mychailo of Chernigiv

Mikhail Vsevolodovich (c. 1185 – 20 September 1246), known as Michael or Mikhail of Chernigov, was Grand Prince of Kiev (1236–1239; 1241–1243); he was also Prince of Pereyaslavl (1206), Novgorod-Seversk (1219–1226), Chernigov (1223–1235; 1242–1246), Novgorod (1225–1226; 1229–1230), and Galicia (1235–1236).
Archaeological evidence reveals that Chernigov towns enjoyed an unprecedented degree of prosperity during his period which suggests that promoting trade was a priority for him. Commercial interests, in part, also motivated him to seize control of Halych and Kiev because they were channels through which goods from the Rhine valley and Hungary passed to Chernigov. He also negotiated commercial treaties and political alliances with the Poles and the Hungarians. He alleviated the tax burden of the Novgorodians and granted their boyars greater political freedom from the prince.
During the Mongol invasion of Kievan Rus’ (1237–1242), Mikhail was defeated and had to flee; in 1246, he was executed by Batu Khan.