The Battle of the Gates of Trajan (Bulgarian: Битката при Траянови Врата, Greek: Μάχη στις Πύλες του Τραϊανού) was a battle between Byzantine and Bulgarian forces in the year 986. It took place in the pass of the same name, modern Trayanovi Vrata, in Sofia Province, Bulgaria. It was the largest defeat of the Byzantines under Emperor Basil II. After the unsuccessful siege of Sofia he retreated to Thrace, but was surrounded by the Bulgarian army under the command of Samuil in the Sredna Gora mountains.