Ratko Mladic was Bosnian Serb leader Radovan Karadzic's army chief throughout the Bosnian war.
Mr Mladic led Bosnian Serb troops throughout the 1992-1995 war
Along with Mr Karadzic, he came to symbolise the Serb campaign of ethnic cleansing of Croats and Muslims and is one of the most wanted suspects from the Bosnia conflict.
He has been indicted by the UN war crimes tribunal on charges of genocide and other crimes against humanity - including the massacre of at least 7,500 Muslim men and boys from the town of Srebrenica in 1995.
Having lived freely in Belgrade for some time, Mr Mladic disappeared from view when former Yugoslav President Slobodan Milosevic was arrested in 2001.
Starting in October 2004, former aides to Mr Mladic began surrendering to the war crimes tribunal, as Belgrade came under intense international pressure to co-operate.
They included Radivoje Miletic and Milan Gvero, both accused of involvement in ethnic cleansing.
Speculation mounted that Mr Mladic would soon be arrested when Radovan Karadzic was arrested in Belgrade in July 2008.
Ratko Mladic was born in Bosnia, in the village of Kalinovik, in 1942.
He was brought up in Tito's Yugoslavia, becoming a regular officer in the Yugoslav People's Army.
Complicity in genocide
Crimes against humanity
Violations of laws or customs of war
As the country began to disintegrate in 1991, he was posted to lead the Yugoslav army's 9th Corps against Croatian forces at Knin.
Later, he took command of the Yugoslav Army's Second Military District, based in Sarajevo.
Then, in May 1992, the Bosnian Serb Assembly voted to create a Bosnian Serb army, appointing Gen Mladic commander.
He is considered to have been one of the prime movers in the siege of Sarajevo and in 1995 led the Serb onslaught against the UN-protected enclave of Srebrenica, the worst atrocity in Europe since World War II.
Bosnian Serb forces laid siege to the Srebrenica enclave, where tens of thousands of civilians had taken refuge from earlier Serb offensives in north-eastern Bosnia.
The Serb forces bombarded Srebrenica with heavy shelling and rocket fire for five days before Mr Mladic entered the town accompanied by Serb camera crews.
The next day, buses arrived to take the women and children sheltering in Srebrenica to Muslim territory, while the Serbs separated out all Muslim men and boys from age 12 to 77 for "interrogation for suspected war crimes".
In the five days after Bosnian Serb forces overran Srebrenica, at least 7,500 Muslim men and boys were murdered.
After the end of the Bosnian war, Mr Mladic returned to Belgrade, enjoying the open support and protection of Mr Milosevic.
He lived openly in the city - visiting public places, eating in expensive restaurants and even attending football matches until Mr Milosevic's arrest.
Some reports say he took refuge in his wartime bunker in Han Pijesak, not far from Sarajevo, or in Montenegro.
Other reports say he remained in or near Belgrade. Former UN war crimes tribunal's chief prosecutor Carla Del Ponte claimed both he and Mr Karadzic were in the city in February 2004.
He is reported to have been suffering from bad health.
In April 2005, Serbian Foreign Minister Vuk Draskovic said Serbian security agents knew Mr Mladic's whereabouts. The head of the intelligence agency described the allegations as "ridiculous".