LOS ANGELES: It was a storybook marriage in 1986 on a spring weekend on Cape Cod that united a princess of an American political dynasty, Maria Shriver, and the gap-toothed muscle-clad movie star famous enough to be known by one name, Arnold. Former California Gov. Arnold Schwarzenegger and Shriver announced their separation late Monday, cleaving a sometimes-turbulent 25-year relationship after “a time of great personal and professional transition for each of us,” the couple said in a joint statement. The breakup comes about four months after Schwarzenegger ended a bumpy, two-term run as California governor, a job his wife never wanted him to pursue. Since then, Schwarzenegger, 63, has been fashioning a role as an international advocate for green energy, giving speeches and lining up work in Hollywood. Shriver, 55, has guested-edited an edition of Oprah Winfrey's magazine. The joint statement, issued by a spokesman for Schwarzenegger, said the two were working on the future of their relationship while living apart and they would continue to parent their four children together.