catch is it's a myth - there is no evidence to show Tynwald was a 'parliament' until 16th century or so - there is a good argument to show that it developed out of a pre-Norse Celtic King making ceremony that was adapted as an Althing (ie meeting of key men of land) by Norse then later it appears as a court to settle legal disputes (again apparently drawing on earlier Celtic models) - even in 1411 document it states: Alsoe we give for Law, that,the Lord or his Lieutennant may hold a Court or Tinwald wheresoever pleaseth him and doe Execution as oft, and whereas pleaseth him, within his Land of Mann, except the Passion Week, at which Time Execution of Life and Lymne ought not to be done;'

But myths are necessary to any nation