The Bulgarian Empire refers to two historical states that existed in the region of modern-day Bulgaria. The First Bulgarian Empire was established in 681 AD and became a significant power in Southeast Europe, known for its cultural and political influence. It reached its peak under the rule of Tsar Simeon I in the 10th century, expanding its territory and promoting the spread of Slavic literacy and the Cyrillic alphabet. The Second Bulgarian Empire emerged in the late 12th century after a successful uprising against Byzantine rule. It lasted until the late 14th century, marked by territorial expansion and cultural revival. The empire faced challenges from the Ottoman Empire, leading to its eventual decline and incorporation into Ottoman territory by the late 14th century.