BORGA (Finnish Porvoo)  , a seaport in the province of Nyland, grand duchy of Finland, situated at the entrance of the river Borg& into the Gulf of Finland, about 33 M. by rail N.W. of Helsingfors . Pop . (181o) 1693; (1870) 3478; (1904) 5255 . It is the seat of a Lutheran bishopric which extends over the provinces of Viborg and St Michel with portions of Tavastehus and Nyland; it possesses a beautiful cathedral, and a high school (where the well-known Finnish poet Runeberg lectured for many years), and is the seat of a court of appeal . The weaving of sail-cloth and the manufacture of tobacco are the principal industries, and the chief articles of trade are wood, butter and furs . Borg& was once a city of great dignity and importance, but the rapid growth of Helsingfors has somewhat eclipsed it . In 1809, when the estates of Finland were summoned to a special diet to decide the future of the country, Borg& was the place of meeting, and it was in the cathedral that the emperor Alexander I. pledged himself as grand duke' of Finland to maintain the constitution and liberties of the grand duchy .