Thackeray began his professional career as a cartoonist with the English-language daily, "The Free Press Journal" in Bombay (now Mumbai), but he left the paper in 1960 to form his own political weekly, "Marmik". His political philosophy was largely shaped by his father Keshav Sitaram Thackeray, a leading figure in the Samyukta Maharashtra (United Maharashtra) movement, which advocated the creation of a separate linguistic state for Marathi speakers. Through "Marmik", Bal Thackeray campaigned against the growing influence of non-Marathis in Bombay. In 1966, Thackeray formed the Shiv Sena party to advocate for the interests of Maharashtra in Bombay India political and professional landscape, and against certain segments of Bombay's Muslim population.