For ten points, identify this son of a Greek woman and Murad I, who was nicknamed "Thunderbolt".
This ruler was repulsed by the Wallachians under Mircea at the battle of Rovine, and he was the husband of Hafsa and Devlet. This father of Ertugrul and Musa Celebi was successful against a crusade launched against him by John Paleologus which culminated in his victory at Nicopolis and successful siege of Constantinople. This man ascended to the throne after the Battle of Kosovo, where his father died, and this ruler is notable for being captured by Tamerlane at the battle of Ankara, which he lost. For ten points, identify this son of a Greek woman and Murad I, who was nicknamed "Thunderbolt".
This ruler was repulsed by the Wallachians under Mircea at the battle of Rovine, and he was the husband of Hafsa and Devlet.
{Bayezid I} (accept {Bayezid the Thunderbolt} until mention)