Diet of Porvoo
During the Finnish War between Sweden and Russia , the four Estates of Russian occupied Finland ( "Nobility , Clergy , Burghers and Peasants" ) were assembled at Porvoo " ( Borgå ) " by Tsar Alexander I , the new Grand Prince of Finland , between 25 March and 19 July 1809 . 
<triplet> Finnish War <subj> Sweden <obj> participant