Simplify the following text for a Grade 12 native English-speaking person.
Original: The Rump Parliament was the name given to Parliament until 1660 of the English Parliament that followed the Long Parliament , after Pride 's Purge of December 6 1648 had removed those Members of Parliament that were against the plan to try King Charles I for high treason .
Simplified: The Rump Parliament is the name of the English Parliament after Colonel Pride purged the Long Parliament on 6 December 1648 of those members hostile to the Grandees ' intention to try King Charles I for high treason .