ac·ces·sion /əkˈseʃən/ noun 1 [uncountableU]PGO an official process in which someone becomes king, queen, president etc 登基,即位;就职 → successionaccession of the accession of James I 詹姆斯一世即位
accession to power/to the throne (=the act of becoming king, queen, president etc) 登上权位/王位