Says the guy that thinks the Westminster system is limited to Britain and it's former colonies, that military ROE prevents killing civilians in order to get at threats, that losing everything is equal to losing half of everything, that Brazil is more of a sovereign nation than the UK and that "best" equals "first."
Oh, and by the way, Sejm wasn't what I'd consider a true parliament until the 1400s. Included only high-ranking nobles prior to that. In contrast, it was 1265 when the first elections were held for British Parliament, and the franchise was extended to Knights, who were not necessarily nobles at birth, and were considered to be very low-ranking unless in possession of another title.
For people who really don't like monarchy, you are surprisingly willing to designate nobility-only councils as "parliaments."