 After receiving a law degree in 1907, Sleževičius returned to Lithuania and joined the Lithuanian Democratic Party (LDP).For the following five years, he practiced the legal profession, participated in cultural activities (particularly in theater performances of the Rūta Society) and served as the chief editor of "Lietuvos ūkininkas" (1907–12), and another newspaper "Lietuvos žinios" (1910–12).When the German army occupied Lithuania in 1915, Sleževičius left for Russia.