Lazarević managed to take power in the country, bolstered by the reputation and work of his mother Milica, who was also politically active.
The Lazarević–Branković conflict continued.
In December 1402, the Republic of Ragusa expressed great regret regarding the conflicts in Serbia.
Sultan Bayezid died in Tatar captivity in March 1403, which ignited a war between his four sons.
There are accounts that Lazarević and Süleyman agreed to a truce shortly after the battle.
Through the Gallipoli treaty in early 1403, Süleyman promised not to interfere in Serbia, on the condition that Lazarević accept his obligations towards the Ottoman Empire, which were in effect prior to the Battle of Ankara, and consisted primarily of tribute and military support.
Lazarević reneged on his previous obligations and continued fighting Branković and the Ottomans.

Around this time, the Lazarević brothers had a falling-out.
The rift apparently stemmed from Vuk's perception that he had not emerged from the battle as a victor.
Lazarević complained about the casualties under Vuk's command and wanted him to train in the art of war.
Lazarević took to instructing his brother in military matters, but Vuk felt slighted after Lazarević said "some hard words" during instructions.
Feeling hurt, with a gap between them, Vuk "waited some time, and finding the right time" ran off to Süleyman in the summer of 1403.
Kalić believes that there was also a disagreement on the division of lands, while Blagojević believes that Lazarević's continued opposition to the Ottomans in light of the truce played a role.
Vuk thus decided to leave the country and enter the ranks of Süleyman Çelebi.

In order to retain his independence from the Ottomans, who were closing in from the south, Lazarević turned to the Kingdom of Hungary, which could be counted on militarily.
After becoming a Hungarian vassal in 1403, Lazarević was offered peace by the Ottomans on his terms, and the Despotate was no longer a subject of the Ottoman Empire.
Vuk returned to the Despotate shortly thereafter and the brothers ruled in accord.
The Ottoman–Serbian peace, Hungarian–Serbian alliance, Hungarian ceding of large territories in the north to the Despotate, and the merger of Vlatković's province to Lazarević's domain, resulted in Lazarević expanding his claims on all the Serbian lands.
Lazarević managed to take power in the country, bolstered by the reputation and work of his mother Milica, who was also politically active. The Lazarević–Branković conflict continued. In December 1402, the Republic of Ragusa expressed great regret regarding the conflicts in Serbia. Sultan Bayezid died in Tatar captivity in March 1403, which ignited a war between his four sons. There are accounts that Lazarević and Süleyman agreed to a truce shortly after the battle. Through the Gallipoli treaty in early 1403, Süleyman promised not to interfere in Serbia, on the condition that Lazarević accept his obligations towards the Ottoman Empire, which were in effect prior to the Battle of Ankara, and consisted primarily of tribute and military support. Lazarević reneged on his previous obligations and continued fighting Branković and the Ottomans.
Around this time, the Lazarević brothers had a falling-out. The rift apparently stemmed from Vuk's perception that he had not emerged from the battle as a victor. Lazarević complained about the casualties under Vuk's command and wanted him to train in the art of war. Lazarević took to instructing his brother in military matters, but Vuk felt slighted after Lazarević said "some hard words" during instructions. Feeling hurt, with a gap between them, Vuk "waited some time, and finding the right time" ran off to Süleyman in the summer of 1403. Kalić believes that there was also a disagreement on the division of lands, while Blagojević believes that Lazarević's continued opposition to the Ottomans in light of the truce played a role. Vuk thus decided to leave the country and enter the ranks of Süleyman Çelebi. 
In order to retain his independence from the Ottomans, who were closing in from the south, Lazarević turned to the Kingdom of Hungary, which could be counted on militarily. After becoming a Hungarian vassal in 1403, Lazarević was offered peace by the Ottomans on his terms, and the Despotate was no longer a subject of the Ottoman Empire. Vuk returned to the Despotate shortly thereafter and the brothers ruled in accord. The Ottoman–Serbian peace, Hungarian–Serbian alliance, Hungarian ceding of large territories in the north to the Despotate, and the merger of Vlatković's province to Lazarević's domain, resulted in Lazarević expanding his claims on all the Serbian lands.
Battle of Tripolje