They were founded in 1950 as the "Mainichi Orions". In 1958, they changed their name to the "Daimai Orions", the "Tokyo Orions" in 1964, the "Lotte Orions" in 1969, and finally the Chiba Lotte Marines since 1992. Chiba Lotte Marines has been a Pacific league champion six times, 1950, 1960, 1970, 1974, 2005, and 2010. Then, 4 times they won Japan series, 1950, 1974, 2005, and 2010.