The blockade or encirclement of Belgrade refers to the Serbian rebel blockade of Belgrade, the capital of the Sanjak of Smederevo (or "Belgrade Pashalik"), initially in the hands of the Dahije (renegade Janissaries) that had wrested the power in the province, and then against the Ottoman Empire itself, during the First Serbian Uprising. It included a range of skirmishes in the years of 1804–1806, culminating in the assault and final siege of Belgrade.

Background

The Dahije (renegade Janissaries) wrested the Belgrade Pashalik and murdered the Vizier Hadji Mustafa Pasha in 1801, and instead of the Porte dealing with the tyranny or sending an investigative commission, it sent pashas according to the Dahije's wishes. The Slaughter of the Knezes in late January prompted the Serbs to rise up against the Dahije. After the burning of the Inns and wounding of Dahije leader Aganlija at Drlupa, Karađorđe went with his rebel army to meet with Sima Marković and Janko Katić in the Belgrade nahiya on 25 February and at the Lipe Assembly, the first siege line towards Belgrade was set up with Sima holding Železnik with his knežina army, Katić holding Kneževac with his Turija knežina army, and Vasa Čarapić holding Avala with his Grocka knežina army. The plan was to block the city, stop the Dahije from entering Serb villages, and preventing resupply. Karađorđe then went to the Smederevo nahiya where the blockade of Smederevo was organized. After the takeover of Rudnik and Valjevo by 18 March, and the tight blockade of Šabac and Smederevo, the strategical encirclement of Belgrade could be said to have been finalized.

At Belgrade, the Vizier was Agha Hasan Pasha, who the Serbs pretendedly recognized as such. The Dahije were the true rulers of the Belgrade Pashalik, and Hasan Pasha had no powers nor influence., Hasan Pasha informed the Grand Vizier about events in the Serb uprising against the Dahije.

March–April 1804

The rebel Belgrade defensive line was not uniform, and Dahije dispatches crossed it at times, such as on 3 March when a Janissary unit clashed with a rebel army numbering 500 towards Ostružnica and was partly destroyed with prisoners, according to a Semlin military command report. A retaliatory Dahije expedition was made on 14 March, resulting in 1,000 Serb refugees crossing over to Habsburg-held territory around Jakovo. In the following days, Dahije units of 200–400 men sortied each day, and Dahije leader Mula Jusuf led a unit of 300 cavalry that killed a number of civilians at Železnik and then went to Ostružnica, from where the rebels retreated into the woods, and where the church was burnt down and all movable property looted, with seven heads put on spears and paraded into Belgrade. Another Dahije attack on a 30-man-unit at Avala gained them more trophy heads. On 19 March the Belgrade cavalry exited the Fortress and went for Ritopek and Vrčin, where they found a rebel trench and were reinforced with 300 men. That same day, kabadahija Tosun-aga went with 80 men by boat to Grocka, which was about to be attacked by the rebels. These Dahije sorties were made to pressure the rebels and disperse them from the environs of Belgrade. At that time, the Dahije awaited reinforcements of mercenaries (kircali) who were located in the Sanjak of Niš, to the southeast of the Pashalik. The Dahije sent another of their leaders, Kučuk-Alija, with 600 cavalry to gather reinforcements, mercenaries and supplies, towards Kragujevac and Jagodina.

Bad weather resulted in a failed siege of Jagodina in which the Serbian rebels were defeated and dispersed, around the last day of March. Karađorđe inspected the Ostružnica–Višnjica line and a 40-men rebel cavalry unit surprise attacked a Belgrade Turk contingent near Mokri Lug on 1 April. The Serbian rebels then retreated towards Žarkovo and Kneževac, from where a detachment attacked a Dahije meyhane at Boleč. 1,000 rebels remained in the encirclement of Belgrade, controlling all major crossings and destroying river bridges near Belgrade. The encirclement of Belgrade was strengthened with Vasa Čarapić at Avala, Đorđe Milovanović at Železnik, Miloje Trnavac and Ranko Marković around Ostružnica. Muhasil Suleyman Agha wrote to the Porte on 6 April about the harsh position of besieged Belgrade. Čarapić defeated a Janissary unit of 230 men under Mula-Jusuf near Mirijevo on 15 April. After the first battle at Jagodina, the Serbian rebels mustered a new army and planned for a better attack, and succeeded with an assault on Jagodina on 16 April led by Karađorđe, killed 300, captured many, and forced Kučuk-Alija to flee. By now, only Belgrade, Smederevo and Požarevac were among important cities held by the Janissaries, all blocked by the rebels. After the victory at Jagodina, smaller rebel units pursued Kučuk-Alija through Šumadija, successfully ambushing twice in 17–18 April. A French report speaks of a Serbian provocation on 17 April that ended with an ambush of 300–400 Janissaries likely near Mokroluški Creek, leaving at least 50 dead. Upon the return of Kučuk-Alija to Belgrade, he improved the defense of the city by cleaning the trenches and setting up parapets, among other things. The rebels evacuated the Serb civilians in the Belgrade environs to the hinterland, mainly Ostružnica, by now an important rebel camp. A rebel incursion into Vračar failed on 20 April, with one dead and 12 captured. An Austrian newspaper reported on the defeat of 40 Turks who looted outside the Belgrade city, with 30 of them killed, on 24 April. It was believed that by late April, there were outposts outside Belgrade numbering some 4,000 rebels. The Belgrade yerli (native Muslims) contemplated settling relations with the Serbs; Gavrilo Kovačević claimed that they twice sent secret letters to the Serbs asking them take over the city, but they were unable to do so, as they were unready and Karađorđe engaged Kučuk-Alija at Jagodina.

May–July 1804 According to Karađorđe's captain Petar Jokić, Čarapić was ordered to set up a trench at Rakovica, Katić at Resnik, while Sima was at Železnik where there were several smaller trenches, in the days prior to Karađorđe's and his Jasenica troops' stay at Ostružnica during Orthodox Easter (). At the Zemun Meeting (10 May), mediated by the Habsburg military command in Syrmia, the rebels and Dahije–Sanjak representatives failed to come to an agreement; at the end of discussions the Serbs made clear that they would all rather die than let the Dahije stay in Belgrade, and that they soon, with 20,000 men would assault Belgrade to deal with the Dahije once and for all. Karađorđe supported the siege of Požarevac in May, during which the Turk Belgrade garrison attacked the Valjevo nahija army at Careva Ćuprija in Topčider, but was repelled by commanders Matija Nenadović and Luka Lazarević who proceeded to attack the Muslim-inhabited Savamala that was abandoned for the trench at Varoš-kapija during the garrison's retreat from Topčider. After the takeover of Požarevac (late May) and Smederevo (4 June), only Belgrade remained outside rebel control in the north of the Belgrade Pashalik. Karađorđe, Jakov Nenadović and Milenko Stojković went to Vračar. Karađorđe organized a tighter blockade and reinforced the troops at Topčider and set up two cannons there. A camp and military church was set up at Topčider. On the road to the Stambol Gate, another camp was set up under the command of Čarapić. The Valjevo army at Topčider paid for Austrian intelligence in Semlin (Zemun) on Turk attacks, and were warned through burning of straws and bulrush, and were also informed by Zemun merchants who worked in Belgrade.

In mid-June 1804, a large Serbian rebel army with the most important commanders mustered outside Belgrade. There are claims of up to 16,000 rebels, out of which 6,000 planned to assault the city. At this point, the Sultan issued a ferman (decree) to Karađorđe to not attack the city, as the Sultan had sent for an Ottoman Bosnian army to aid the rebels against the Dahije. The rebels aborted the assault. Vizier Bekir Pasha of Bosnia was given the mission to stop the fighting between the Dahije and Serbs, to bring peace and security to the Belgrade Pashalik and Ottoman frontier.,

Bekir Pasha mustered an army of over 3,000, 3,500 or 4,600 Ottoman Bosnian soldiers and various sipahi and from Zvornik sent a mühür-sahib (official seal carrier) to Karađorđe and the Serbian leadership at Vračar, and a letter to the Dahije in Belgrade, that he brought the Sultan's ferman and was commissioned to make peace between the Dahije and Serbs. The mühür-sahib stayed at Vračar for five days, and was hosted nicely by the Serbs, while the Dahije refused to meet with him. Karađorđe approved of Bekir Pasha's arrival into Serbia, also on the advice of Hadji Sali Bey of Srebrenica, who was a pen pal of Matija Nenadović and had informed the Porte about the Dahije abuse and helped its decision in sending this commission.

Karađorđe sent knez Milovan Grbović with some Šabac kmets (serfs) and 50 cavalry to meet with Bekir at the Drina on , or many Mačva kmets welcomed Bekir at the Drina and Grbović welcomed him at Šabac on . Grbović escorted Bekir's army to Palež (Obrenovac) where Jakov Nenadović, Sima Marković and Janko Katić with 500 or 600, cavalry welcomed Bekir Pasha and let him spend the night. The trio escorted him, arriving at Žarkovo and Bekir Pasha made camp at a mansion in Bele Vode. The Serbian leadership decided that Bekir Pasha stay at Bele Vode until the matter with the Dahije was handled. The four Dahije leaders had escaped Belgrade on chaikas down the Danube to Adakale, as they feared a conspiracy by mercenary leader Alija Gušanac and not knowing Bekir Pasha's intention with them. The dating of their escape is unclear in historiography. The historian K. Nenadović believed that Bekir had in fact allowed the four leaders to secretly leave., Upon hearing of the Dahije leaders' flight, Alija Gušanac looted their mansions, and took control of Belgrade. Karađorđe ordered for a parade with 4,000 men at Topčider, for Bekir to see. From Vračar, Karađorđe took Matija Nenadović and 200 of the best cavalry with him to Bele Vode, where outside Bekir's camp, these with Katić's cavalry encircled from three sides. According to K. Protić, there were 2,000 Serb cavalry at Bele Vode, as to protect from a potential attack. Karađorđe, Matija, Jakov, Sima and Katić entered Bekir's tent. Bekir promised improvements on the Serbs' status, while Karađorđe stressed that they would not stop until the Dahije were caught dead or alive, and knowing that the Dahije could muster an army of the Vidin Pashalik and attack at any time, both sides agreed for them to be assassinated., , Bekir had insufficient troops to defend against a potential Serb attack, witnessing the strength in the rebel camps in the area, and wanted to enter the Belgrade Fortress as soon as possible. Milenko Stojković carried out the mission, besieging the house at Adakale where the Dahije stayed, shooting them and having their heads cut off and sent to Belgrade where they were put on stakes., ,

Karađorđe ordered the army to escort and parade Bekir into Belgrade, with gun, and cannon salute from two iron cannons. According to K. Nenadović the sight of the Serbian army and cannon salute visibly scared Bekir and his army.

Ceasefire