Eventually, in autumn 1916, a PNL cabinet and King Ferdinand I announced Romania's support for the Entente; Romanian troops briefly entered Transylvania, but Romania was in turn invaded by the Central Powers. Bianu stifled his opposition, but did not openly criticize all the Central Powers. In September, shortly after the Battle of Turtucaia, he penned in "Viitorul" an article specifically targeting the Kingdom of Bulgaria and the Bulgarians in Romania, whom he called "venomous snakes". According to historian Lucian Boia, this is "possibly the most anti-Bulgarian writing ever published in Romanian"; "Bianu says nothing about the Austro-Hungarians or Germans, as if Romanians had only been at war with the Bulgarians in 1916!"