Related to Apafi on his mother's side, he gained considerable political influence and even became Chancellor of Transylvania in 1688.
Lord Apafi was a weak ruler, so the principality was actually run by his wife Anna Bornemisza in cooperation with Teleki.
After his unsuccessful siege of Prešov, his star among the insurgents began to decline, and the Kurucs chose Imre Thököly as their leader.
In August 1690, Imre Thököly invaded Transylvania at the head of an army consisting of Kurucs and Turks.
On 21 August, he defeated the Imperial troops commanded by Michael Teleki and the Austrian General Donat Johann Heissler von Heitersheim in the Battle of Zernest.