Short answers, pulled from the story.
The Communist International began recruiting volunteers for Spain in September 1936. The Comintern agreed to start recruiting international volunteers one week after the London meeting of the Non-Intervention Committee confirmed that Western democracies would not provide military aid.
Volunteers arrived at Albacete, which served as the headquarters inside the Gran Hotel. André Marty served as commander while Luigi Longo acted as Inspector-General and Giuseppe Di Vittorio as chief political commissar.
About 32,000 foreigners volunteered to defend the Spanish Republic between 1936 and 1938. France provided the largest number of volunteers with estimates ranging from 8,962 to 9,000 men.
The Republican government announced the decision to disband International Brigades on the 21st of September 1938 before the League of Nations. The operation was dissolved officially on the 23rd of September 1938 by Prime Minister Juan Negrín.
Two former brigadiers became prime ministers: Mehmet Shehu in Albania during 1954 and 1981 and Ferenc Münnich in Hungary during 1958 and 1961. Rodoljub Čolaković served as prime minister of Bosnia and Hercegovina until 1948.