The Conservative administration of Rodmond Roblin, which had governed Manitoba since 1900, was forced to resign from office in early 1915 as the result of a corruption scandal.[4] Although the Liberals held a minority of seats in the legislature, they were called on by the province's Lieutenant Governor to form a new government. Armstrong was appointed to Premier Norris's first cabinet on May 12, 1915, as Provincial Secretary and Municipal Commissioner. Armstrong was then re-elected by a landslide in the 1915 provincial election, in which the Liberals won 40 seats out of 47.