What new country was created in 1918 from Czech and Slovak territories?

The new country created in 1918 from Czech and Slovak territories was Czechoslovakia. It was established on 28 October 1918 as the Austro-Hungarian Empire collapsed at the end of World War I.

The state joined the historic Czech lands of Bohemia, Moravia, and part of Silesia with Slovakia, which had been under Hungarian rule within Austria-Hungary. Its creation reflected both Czech and Slovak political cooperation and the broader postwar movement toward national self-determination.

Czechoslovakia's founders included Tomáš Garrigue Masaryk, who became its first president, along with Edvard Beneš and Slovak leader Milan Rastislav Štefánik. The country also included other ethnic communities, particularly Germans, Hungarians, Rusyns, and Poles, making its borders and internal politics complicated.

The country survived the turbulent interwar period but was weakened by the 1938 Munich Agreement, which transferred the Sudetenland to Nazi Germany. After World War II it became a communist state, and in 1993 it peacefully divided into the Czech Republic and Slovakia in an event often called the Velvet Divorce.