The Macedonian Youth Secret Revolutionary Organization or MMTRO was a secret pro-Bulgarian youth organization established by the Internal Macedonian Revolutionary Organization, active in Macedonia between 1922 and 1941. The statue of MMTRO was approved personally by the leader of the IMRO, Todor Alexandrov. The aim of MMTRO was in concordance with the statue of IMRO – unification of all of Macedonia in an autonomous unit within Greater Bulgaria. It was established in 1921–1922 in Zagreb by students from Vardar Macedonia. It soon gained influence amongst Macedonian Bulgarians in Belgrade, Vienna, Graz, Prague, Ljubljana and other places where Macedonian students lived. In a short time its influence had spread amongst the student youth in Yugoslav and Greek Macedonia and across Europe. After the Skopje Student Trial of MMTRO followers, the local intelligentsia devolved the organizational structure even further. When in 1941 the Yugoslav and Greek rulers were replaced by Bulgarian administration, the organization became marginalized, and ultimately dissolved.