Ali Pasha, one of Murad's most favoured commanders, left Üsküp  in June 1444 with an army of 25,000-40,000 troops and headed in Albania's direction. Having brought together an army of 15,000 men  from the League of Lezhë, Skanderbeg exhorted to his soldiers the importance of the upcoming campaign. Orders were given for the distribution of soldiers' pay and for religious services to be held. Afterwards, Skanderbeg and his army headed towards the planned place of battle in Lower Dibra, which is thought to be the Plain of Shumbat, then called the Plain of Torvioll, north of Peshkopi. On the way there, he marched through the Black Drin valley and appeared at the expected Ottoman entry point. Skanderbeg had chosen the plain himself: it was 11.2 kilometres  long and 4.9 kilometres  wide, surrounded by hills and forests. After camping near Torvioll, Skanderbeg placed 3,000 men under five commanders, Hamza Kastrioti, Muzaka of Angelina, Zecharia Gropa, Peter Emanueli, and John Musachi, in the surrounding forests with orders to attack the Ottoman wings and rear only after a given signal. While Skanderbeg was preparing his ambush, the Ottoman Turks under Ali Pasha arrived and encamped opposite his forces. The night before the battle, the Ottomans celebrated the coming day, whereas the Albanians extinguished all their campfires and those who were not on guard were directed to rest. Parties of Ottomans made approaches to the Albanian camp and provoked Skanderbeg's soldiers, but they remained quiet. Skanderbeg sent out a scouting party to obtain information about the Ottoman army and ordered his cavalry to engage in small skirmishes.
Where did Skanderbeg's soldiers arrive first, the Black Drin valley or Lower Dibra?
the Black Drin valley