The Ottoman wars in Europe, also known as the Ottoman Wars or Turkish Wars, were a series of military conflicts between the Ottoman Empire and various European states dating from the Late Middle Ages up through the early 20th century. The earliest conflicts began during the Byzantine–Ottoman Wars in the 13th century, followed by the Bulgarian–Ottoman Wars and the Serbian–Ottoman Wars in the 14th century. Much of this period was defined by Ottoman expansion into the Balkans and modern-day Serbia, which allowed the Empire to gain a foothold in eastern Europe. The Ottoman Empire made further inroads into Central Europe in the 15th and 16th centuries, culminating in the peak of Turkish territorial claims in Europe. There was a backslide in Ottoman military dominance after the unsuccessful Siege of Vienna in 1529 and the Ottoman-Habsburg wars. European powers began to consolidate against the Ottomans and formed the Holy League, reversing a number of Ottoman land gains during the Great Turkish War of the late 1600s.