With the conquest of Edirne, the Turks began to advance in the Balkans. In 1363, Lala Sahin Pasha campained to Bulgaria and invaded Filibe, Commander Evrenos Bey captured Serez. Turkish clans sent to settle in the new lands. As the result of the conquests of Edirne and Filibe, Papa Urban V provoked a new crusade. The Crusade was emerged by Serbians, Bulgarians, Hungarians, Bosnians and Wallachians. They had marched through Edirne. Ottoman Commander Haci Ilbey benefited from the crusaders’ irregular advance along the valley of Maritsa and he divided his forces into three and made a sudden attack at night. With this plan he victoriously defeated the crusades(1364).

This victory was named as the War of Sirp Sindigi in the history and it defined the Turkish Sovereignty in Roumelia. The Ottoman forces went to Bulgaria next and conquered the upper part of Bulgaria. The Bulgarian King Yuvan Sisman accepted the Ottoman sovereignty and gave his sister Maria to Murad (1369).

Murad campaigned to Macedonia and with the victory of Crimea in 1371, Macedonia was annexed into the Ottoman territories. Serbian King Lazar, accepted the Ottoman sovereignty and was assigned to annual tax. The Turkish forces under Candarli Hayreddin Pasha’s command won the victories of Salonica (1374), Nis (1375), Istip, Manastir, and Pirlepe (1382). The Ottoman forces campaigned to Albania and to Bosnia-Herzegovina. In 1385, Ohri was conquered. In the same year the Battle of Savra had won in Albania. One year later Sofia was conquered.

In 1381, Sehzade Bayezid was married to Devlet Sultana the daughter of the Germiyan Monarch Suleyman Shah and Kutahya, Simav, Egrioz, and Tavsanli were given to the Ottomans as a wedding gift. In the same year the Hamidogullarý sold six cities to the Ottomans. While the conquests in the Balkans were continuing, Murad went to Anatolia. In 1386, the first Ottoman – Karaman battle was fought in the Konya plain.