The Agram Trial or Zagreb Trial (known as the "High treason trial" in Serbo-Croatian, veleizdajnički proces) was the trial of 53 Serbs in Austria-Hungary, who were accused of conspiracy to overthrow the state and place Croatia-Slavonia under Serbian rule. The Austro-Hungarian government had discredited the Croat-Serb Coalition and created an internal discussion accusing Serbs of massive conspiracy. The Pure Party of Rights, led by Josip Frank, participated in attacks on the accused Serbs (most supporters of the Serb Independent Party) and also the Croat-Serb Coalition, with government directives. Arrests were made during the Bosnian crisis, made to justify the annexation of Bosnia and Herzegovina. Some of the accused were held under bad circumstances(a number died before trial), until the trial began in March 1909. The trial caused sensation across Europe, and was viewed as a blatant attempt to crush Slavic majority politics in Croatia-Slavonia. After many years of the Croatian Serbs and Croatian Croats splitting the Slavic vote in the Croatian Diet elections the Fiume "Croat-Serb Coalition" agreement of 1905 resulted in a landslide victory for the Slavs in the next Croatia election. This was catastrophic for the Austro-Hungarians ruling minority who were faced with handing control of the country, for the first time, to the Slavs. The accusations of sedition against the newly elected members of the Croatian government arrived just in time to put most of the Slavic members of parliament in prison (where they remained for over 2 years without trial) and return control back to the Austro-Hungarians who held nearly a third of the seats in the Diet ex-officio(they held none by election) and hence became the government. Austrian ambassador in Belgrade János Forgách forged documents against the accused Slavs with the help of two Slavic traitors; Djeodje Nastić and Valerian Sergijan Vasić. 31 Slavs were convicted and given 184 years in October 1909. The corruption of the process was revealed in the Friedjung Trial 1909/10 and the arrest of Vasić in 1911 in possession of at least one of the original "door-sized" forgeries. The obvious bias and unreliable evidence led to the defendants' release in 1910 even before completion of their appeal process. The cloud of international suspicion against Serbia at being the puppet masters and instigators of the defendant's alleged sedition provided convenient cover to allow Austro-Hungary to annex Bosnia and Herzegovina in 1909 against the terms of the Berlin Treaty of 1878, without the Serbs being able to muster sufficient international sympathy for the southern Slavic cries for independence to prevent the annexation.
