刘焉(yān )是(shì )汉鲁恭王(wáng )之(zhī )后裔,以汉(hàn )朝宗室(shì )身份,拜(bài )为(wéi )中郎,历任雒阳令,冀州刺史(shǐ ),南阳太守,宗正,太(tài )常等官。后(hòu )因益(yì )州刺史郄(qiè )俭在益州大事聚敛,贪婪(lán )成风(fēng ),加上(shàng )当时天下大乱(luàn ),刘焉欲(yù )取得一安身立命之(zhī )所,割据一(yī )方。于(yú )是刘焉向朝廷求为(wéi )益州(zhōu )牧,封阳城侯,前往(wǎng )益州整饬吏治。后郗俭为黄巾贼(zéi )所杀(shā ),刘焉(yān )进入益州,派张鲁盘(pán )踞汉中,