Jan Szembek
Count Jan Sebastian Szembek was a Polish szlachcic.
He was Recorder of the Crown starting in 1699, Vice-Chancellor of the Crown in 1702, and Grand Chancellor of the Crown since 1712. He was also the starost of Łomża in 1706.
Marshal of the Sejm on December 22, 1701 - February 6, 1702.