The Constantinople or Istanbul trials of 1919–1920 (Ottoman Turkish: عالیه دیوانِ حربِ عرفی. Âliye Divan-ı Harb-i Örfi) were courts-martial of the Ottoman Empire that occurred soon after the Armistice of Mudros, in the aftermath of World War I, and part of the larger movement to prosecute Ottoman war criminals.

The government of Tevfik Pasha decided to prosecute crimes of Ottoman officials, committed primarily against the Armenian population, in national courts. On 23 November 1918, Sultan Mehmed VI created a government commission of inquiry, and Hasan Mazhar Bey was appointed chairman. The formation of a military tribunal investigating the crimes of the Committee of Union and Progress (CUP) was a continuation of the work of the Mazhar commission, and on 16 December 1918, the Sultan officially established such tribunals. Three military tribunals and ten provincial courts were created. The tribunals came to be known as "Nemrud's court", after Mustafa "Nemrud" Pasha Yamulki.

The leadership of the CUP and selected former officials were charged with several offences including subversion of the constitution, wartime profiteering, and the massacres of both Armenians and Greeks. The court reached a verdict which sentenced the organizers of the massacres – Talat, Enver, and Cemal – and others to death. All those sentenced to death were sent a fatwa from the Sheikh al-Islam in the name of Mehmed VI before their execution, as the law stipulated that a Muslim could not be executed without a fatwa from the Sultan-Caliph.

These trials and fatwas also served as means for Mehmed VI to express his disapproval of the accused and legitimize his position, both in relation to his domestic situation with the Muslims in his empire, in the face of the Western powers that emerged victorious in World War I, and to anti-absolutist politicians.

Since there were no international laws in place under which they could be tried, the men who orchestrated the massacres escaped prosecution and traveled relatively freely throughout Germany, Italy, and Central Asia.Power, Samantha. "A Problem from Hell", p. 16-17. Basic Books, 2002. That led to the Armenian Revolutionary Federation's launch of Operation Nemesis, a covert operation conducted by Armenians during which Ottoman political and military figures who fled prosecution were assassinated for their role in the Armenian genocide.

The Turkish courts-martial were forced to shut down during the resurgence of the Turkish National Movement under Mustafa Kemal. Those who remained serving their sentences were ultimately pardoned under the newly-established Kemalist government on 31 March 1923.

Background World War I

Following the reportage by US Ambassador to the Ottoman Empire Henry Morgenthau, Sr. of the Armenian resistance during the Armenian genocide at the city of Van, the Triple Entente formally warned the Ottoman Empire on 24 May 1915 that:

In the months leading up to the end of World War I, the Ottoman Empire had undergone major restructuring. In July 1918, Sultan Mehmed V died and was succeeded by his half-brother Mehmed VI. The Ministers of the Committee of Union and Progress (CUP), including the Three Pashas who ran the Ottoman Government between 1913 and 1918, had resigned from office and fled the country soon afterwards. Successful Allied offensives in Salonika posed a direct threat to the Ottoman capital of Constantinople.Findley, Carter Vaughn. Turkey, Islam, Nationalism, and Modernity. Yale University Press, 2010, p. 215 Sultan Mehmed VI appointed Ahmed Izzet Pasha to the position of Grand Vizier and tasked him with the assignment of seeking an armistice with the Allied Powers and ending Ottoman involvement in the war.Lewis, Bernard. The Emergence of Modern Turkey. Oxford University Press, 1968, p.239

On 30 October 1918, an armistice was signed between the Ottomans, represented by the Minister of the Navy Rauf Orbay, and the Allies, represented by British Admiral Sir Somerset Gough-Calthorpe. The armistice essentially ended Ottoman participation in the war and required the Empire's forces to stand down although there still remained approximately one million soldiers in the field and smallscale fighting continued in the frontier provinces into November 1918.

Surrender of Constantinople

In November 1918, Britain appointed Admiral Sir Somerset Gough-Calthorpe as High Commissioner and Rear-Admiral Richard Webb as Assistant High Commissioner in Constantinople. A French brigade later entered Constantinople on 12 November 1918, and British troops first entered the city on 13 November 1918. Early in December in 1918, Allied troops occupied sections of Constantinople and set up a military administration.

The US Secretary of State Robert Lansing summoned the representatives of the Ottoman Empire, Sultan Mehmed VI and Grand Vizier Damat Ferid Pasha (a founding member of the Freedom and Accord Party). The Paris Peace Conference established "The Commission on Responsibilities and Sanctions" in January 1919.

On 2 January 1919, Gough-Calthorpe requested from the Foreign Office authority to obtain the arrest and handing over of all those responsible for the incessant breaches of the terms of the Armistice and the continued ill-treatment of Armenians. Calthorpe got together a staff of dedicated assistants, including a notable anti-Turkish Irishman, Andrew Ryan, later Sir, who in 1951 published his memoirs. In his new role as the chief Dragoman of the British High Commission and Second Political Officer, he found himself in charge of the Armenian question. He proved instrumental in the arrest of a large number of the (later to be) Malta deportees. These fell broadly into three categories: Those still breaching the terms of the armistice, those who had allegedly ill-treated Allied prisoners-of-war and those responsible for excesses against Armenians, in Turkey itself and the Caucasus. Calthorpe asked for a personal interview with Reshid Pasha, Ottoman Minister of Foreign Affairs, to impress on him how Britain viewed the Armenian affair and the ill-treatment of POWs as "most important" deserving "the utmost attention". Two days later Calthorpe formally requested the arrest of seven leaders of the CUP. While between 160 and 200 people were arrested, another 60 suspected of participating in the massacre of Armenians remained at large.Turkey’s EU Minister, Judge Giovanni Bonello And the Armenian Genocide – 'Claim about Malta Trials is nonsense' . The Malta Independent. 19 April 2012. Retrieved 10 August 2013

Courts-martial

Establishment

The courts-martial were established on 28 April 1919 while the Paris Peace Conference was ongoing. An inquiry commission was established, called the "Mazhar Inquiry Commission", which was invested with extraordinary powers of subpoena, arrest, etc., through which the war criminals were summoned to trial. This organization secured Ottoman documents from many provinces of the Ottoman Empire. Mehmet VI and Damat Ferid Pasha, as representatives of the Ottoman Empire were summoned to the Paris Peace Conference. On 11 July 1919, Ferid Pasha officially confessed to massacres against the Armenians in the Ottoman Empire and was a key figure and initiator of the war crime trials held directly after World War I to condemn to death the chief perpetrators of the genocide.Gunnar Heinsohn: Lexikon der Völkermorde. Reinbek 1998. Rowohlt Verlag. p. 80 (German)Recognizing the 81st Anniversary of the Armenian Genocide . United States Government Printing Office. Retrieved 21 January 2013Armenian Genocide Survivors Remember . Queens Gazette. Retrieved 21 January 2013

The Ottoman Government in Constantinople (represented by Ferid Pasha), foisted the blame on a few members of the CUP and long-time rivals of his own Freedom and Accord Party, which would ensure that the Ottoman Empire received a more lenient treatment during the Paris Peace Conference... The trials helped the Freedom and Accord Party root out the CUP from the political arena. On 23 July 1919, during the Erzurum Congress, General Kâzım Karabekir was issued a direct order from the Sultanate to place Mustafa Kemal Pasha (Atatürk) and Rauf (Orbay) under arrest and assume Kemal's position as Inspector-General of the Eastern Provinces. He defied the government in Constantinople and refused to carry out the arrest.

At that time Turkey had two competing governments in Istanbul and Ankara. The government in Istanbul supported the Turkish trials with more or less seriousness depending on the current government. While Ferid Pasha (4 March – 2 October 1919 and again 5 April – 21 October 1920) stood behind the prosecuting body, the government of Ali Riza Pasha (2 October 1919 – 2 March 1920) barely made a mention of the legal proceedings against the war criminals.Taner Akçam: A Shameful Act: The Armenian Genocide and the Question of Turkish Responsibility, Metropolitan Books, New York 2006 , p. 296 The trials had also blurred the crime of participation in the Turkish National Movement with the crime of the Armenian genocide, and ultimately resulted in increasing support for the government in Ankara that would be led later on by Atatürk.Taner Akçam: A Shameful Act: The Armenian Genocide and the Question of Turkish Responsibility, Metropolitan Books, New York 2006 , p. 351

Procedure The court sat for nearly a year, from April 1919 through March 1920, although it became clear after just a few months that the tribunal was simply going through the motions. The judges had condemned the first set of defendants (Enver, et al.) when they were safely out of the country, but the Tribunal, despite making a great show of its efforts, had no intention of returning convictions. Admiral Gough-Calthorpe protested to the Sublime Porte, took the trials out of Turkish hands, and moved the proceedings to Malta. There an attempt was made to seat an international tribunal, but the Turks bungled the investigations and mishandled the documentary evidence so that nothing of their work could be used by the international court.Shadow of the Sultan's Realm: The Destruction of the Ottoman Empire and the Creation of the Modern Middle East, Daniel Allen Butler, Potomac Books Inc, 2011, , p.211-212

According to European Court of Human Rights judge Giovanni Bonello, 'quite likely the British found the continental inquisitorial system of penal procedure used in Turkey repugnant to its own paths to criminal justice and doubted the propriety of relying on it'. Or, possibly, the Turkish government never came round to hand over the incriminating documents used by the military courts. Whatever the reason, with the advent of power of Atatürk, all the documents on which the Turkish military courts had based their trials and convictions, were 'lost'. Admiral John de Robeck replaced Admiral Gough-Calthorpe on 5 August 1919 as "Commander in Chief, Mediterranean, and High Commissioner, at Constantinople". In August 1920, the proceedings were halted, and Admiral John de Robeck informed London of the futility of continuing the tribunal with the remark: "Its findings cannot be held of any account at all."Public Record Office, Foreign Office, 371/4174/136069 in