Complex sentence: After John Sigismund Zápolya suppressed their rebellion in 1562, many Székely commoners was reduced to serfdom and the autonomy of the seats was reduced and the position of the appointed royal judges was strengthened.
Split into simpler sentences: After John Sigismund Zápolya suppressed their rebellion in 1562, many commoners were reduced to serfdom. The autonomy of the seats was also limited and the position of the appointed royal judges was strengthened.