The Korean legal system is a civil law system influenced by the continental law of Europe, especially German law, through Japan, which colonized Korea from 1910 to 1945. After the Republic of Korea was formed in 1948, many Japanese laws remained entrenched, and their residual impact on Korean legal system is still pervasive, since American law is limited to “individual doctrines” in Korea instead of Korea's judicial institutions and their culture. The Constitution of 1987 proclaims Korea to be a democratic republic, with three branches: the executive, the legislative, and the judiciary. No laws may violate constitutional principles. The Korean judicial system is three-tiered: 1 Supreme Court (highest court); 5 High Courts (intermediate appellate courts); and 13 District Courts (trial courts).