Days after her husband was killed in the Battle of Kronstadt on 17 July 1603, Anna Kornis gave birth to a son in Temesvár, which then belonged to the Ottoman Empire and was capital of the Temeşvar Eyalet (today Timișoara, Romania).
Gabriel Bethlen appointed Székely as judge of Udvarhelyszék and donated Marosújvár Castle (today Ocna Mureș, Romania) and the surrounding villages to him in 1620.