He split his army into several groups and ordered them to march in separate directions through the mountains and remain unseen by the Ottoman forces until the signal to reassemble was given.

On 2 September 1457, Skanderbeg finally gave the order for his armies to regroup and launched a surprise attack on the Ottoman camp, killing and capturing up to 30,000 men.

However, it also marked the high point of the Albanian resistance, beginning a new phase in Skanderbeg's quarter-century long war which would include its fiercest Ottoman invasions.

[8] The Albanians, however, were able to recover their morale when Pope Calixtus III, who had begun to worry that his plans for crusade would be undermined, promised to aid Skanderbeg.

[8] Before the planned crusade commenced, Sultan Mehmed II the Conqueror (Turkish: el-Fātiḥ) decided to march against Hungary and Albania.

In April 1456, Skanderbeg sent Pal Engjëlli, his ambassador to the West, with a letter to Cardinal Domenico Capranica informing the Holy See of his need for aid.

[11] Later that year, İbrahim II of the Karamanid Dynasty tried to create an anti-Ottoman alliance which would include his realm, Skanderbeg, Hunyadi, Calixtus, and Alfonso, all of whom would act in concert to defeat the sultan.

Relations with the Italian state worsened further when Lekë Dukagjini, Skanderbeg's elusive ally in the north, captured Dagnum.

The Venetian rectors continued to provoke Skanderbeg at a time when he had grown relatively weak due to his nephew and one of his most important officers, Hamza Kastrioti, deserting and joining the Ottomans.

[1] Isak bey was an experienced commander who had crushed Gjon Kastrioti's rebellion in 1430 and led the Ottoman counterattack at the Siege of Berat.

Realizing that both Ottoman commanders, Isak bey and Hamza, were familiar with the Albanian terrain and his tactics, Skanderbeg decided to adopt a new means of engagement.

[18] To make it impossible to be followed, Skanderbeg split his forces into several groups and ordered their respective commanders to march through the forests and mountains in different directions and to never assemble or assault the Ottomans unless instructed to do so.

[19] Since he had not yet engaged Skanderbeg, Isak bey decided not to besiege Krujë, Albania's main fortress, until he was sure of the Albanian's fate.

[19] Since Tumenishta had served as the main base for Skanderbeg's forays into the Ottoman camp at the Siege of Krujë (1450), Isak bey and Hamza prepared to annihilate any resistance they would find there.

Still unsure of Skanderbeg's dispositions, the Ottoman commanders strengthened the camp's northern defenses, while the eastern side, in the direction of Tumenishta, remained lightly defended.

[20] Due to Skanderbeg's "disappearance," rumors began to spread that he had fled since he was unable to confront the Ottomans and that his men had betrayed him.

[24] Isak bey tried to send reinforcements to Hamza's men, but the arrival of new Albanian contingents forced him to turn his attention.

A series of cavalry charges and counter-charges kept the battle moving with a rain of missiles and arquebusiers forcing the Ottomans into the heart of the camp.

The fallen Albanian warriors were buried in the Cathedral of St. Mary in the village of Shumri (3 kilometres (1.9 mi) east of Mamurrasi) near the battlefield.

The envoy also tried to settle for a truce between Mehmed and Skanderbeg, but the latter responded that he would only accept if Svetigrad and Berat, which had been lost in 1448 and 1450 respectively, were restored to his state.

[30] This gave Skanderbeg the opportunity to land in Italy and help out Alfonso's son, Ferdinand I of Naples, who had been crowned after his father had died.