In 2006, 18-year-old Kalle Johan Ernesti Holm burned the cathedral and was sentenced to three months in jail.
In 1809 Finland became a semi-autonomous part of the Russian empire and the Porvoo Diet convened in this cathedral:
Between March 25 and July 19, 1809 the four Estates of occupied Finland (Nobility, Clergy, Burghers and Peasants) were assembled at Porvoo (Borgå) by Tsar Alexander I, the new Grand Duke of Finland. The central event at Porvoo was the sovereign pledge and the oaths of the Estates in Porvoo Cathedral on March 29. Each of the Estates swore their oaths of allegiance, committing themselves to accepting the Emperor and Grand Duke of Finland as the true authority, and to keeping the Constitution and the form of government unchanged. Alexander I subsequently promised to govern Finland in accordance with its laws.The events of 1809 are considered to have been more important for the independence of Finland than the official recognition of the independence in 1917: From Helsingin Sanomat:
"Of course I take a slightly reserved stand on the 2017 side of things. From the Finnish perspective, 1809 is a more significant milestone than 1917, when the declaration came and the fledgling state waited to see if any other countries would acknowledge Finland's sovereignty and independent existence", says Klinge.A bronze statue of emperor Alexander I, made in 1909 by Walter Runeberg, is still standing in the cathedral.
"In fact, if we are really scientific about it, the changes that took place in 1917 were of a much lower order of magnitude than those of 1809", he goes on.