Chamberlain was elected party leader following the impeachment of Xavier Gaston from office in 2764; he was elected the new chairman in a landslide by the National Congress following Xavier's impeachment from office. Chamberlain was noted in his tenure for his federalist and conservative beliefs, breaking with traditional policy of statism of former party leaders; Chamberlain took large steps to divert the party from a central government advocate to become more regionalist friendly and pro-market. Chamberlain however still stuck to Fascist Authority Party core values with concerns to central government but did introduced legislation to appeal to small-government supporters.
Erik Chamberlain was remembered for establishing the Hulstrian Monarchist Society with the Imperial Hulstrian Party and the Hulstrian National Party in 2779, the first major national monarchist organization in centuries within the country. With this, Chamberlain became the first Fascist Authority Party chairman to openly push for massive royalist reform in Greater Hulstria that gave new powers to the Monarchy and on top of leaning towards federalism lifted the Fascist Authority Party into new ranks amongst monarchist circles in Hulstria. The creation of the HMS additionally paved the way for a renowed aristocratic presence within the Imperial Crownlands.
Chamberlain furthermore made advances in creating new lines of communication with other parties; in his tenure he was able to establish new alliances with the Hulstrian National Party and the Socialist Party of Greater Hulstria. Erik Chamberlain actually endorsed the party leader of the SPGH for the Governor-Generalship for nearly 20 years while he focused his efforts at building the party at a ground level while strengthing ties with party ally, the Imperial Hulstrian Party. In 2789 after over 20 plus years serving as party chairman, Chamberlain retired from politics, and tapped Friedrich Ewald II to become his successor.