On August 15, 2018, the Bulgarian Post released a souvenir sheet dedicated to the victory of the Bulgarian Khan Tervel over the Arab army that besieged Constantinople in 718.

Tervel - Khan of Danube Bulgaria from the Dulo dynasty ruled the country from 700 to 721. He was a successful and far-sighted ruler, he entered into political relations with Byzantium, concluded favorable trade and alliance treaties. However, the most significant event during the reign of Khan Tervel was the victory over the Arabs in 718 near Constantinople.

In 717, another wave of Arab expansion into Europe began. The Arabs intended to invade Central Europe through the Bosphorus and Dardanelles, passing through Bulgarian lands. Arab troops captured many cities in Thrace, and Constantinople was besieged for the third time. The siege of the city lasted 13 months, the Byzantine Emperor Leo III asked the Bulgarians for military assistance. In 717, Khan Tervel with his army provided decisive assistance to Byzantium, unexpectedly appearing in the rear of the Arabs at the most critical moment. During the battle, most of the land forces were destroyed. In the spring of 718, the Arabs decided to take revenge and give a decisive battle to the Bulgarians, but were defeated, their losses amounted to about 30,000 people. The defeat of the land forces of the Arab commander Maslama predetermined the end of the invasion. This brilliant victory became well known, all European chroniclers noted the enormous merit of the Bulgarian ruler, even calling him "the savior of Europe". Khan Tervel received the title of the Roman Caesar, and was later canonized under the name of Saint Trivelius.

The author of the souvenir sheet is the Bulgarian artist Nenko Atanasov, a teacher at the National Art Gallery. The sheet's background is a geographical map, with a portrait of Khan Tervel in the upper left corner. The stamp features a stylized image of the gates of Constantinople, from where Bulgarian troops are driving out Arab invaders.

The original source of the drawing of two cavalry units was a miniature from the manuscript of John Skylitzes "Byzantine History" ("History of the Byzantine Emperors from 811 to 1057"), or more precisely from his Madrid list. According to the most common hypothesis, the Madrid list was made in Italy in 1158 based on a copy of the original presented to the emperor by Skylitzes himself. The Madrid list contains 574 miniatures, which is why it is considered one of the most significant monuments of Byzantine historical miniatures. The manuscript is kept in the National Library of Spain in Madrid.

On the 54th sheet of the manuscript there is a miniature "Byzantine cavalry pursuing Agar" - this is the image that the Bulgarian artist took as a basis.

The Arab detachment was transferred to the stamp practically unchanged - only the number of horsemen was slightly reduced.

But the Byzantine cavalry turned into a Bulgarian detachment and acquired a colorful leader with a sword in his hand.

The block was published in the amount of 8,000 copies, the denomination of the stamp is 2 leva. The ceremonial presentation of the block and the memorable cancellation of the first day took place in the city of Tervel, also named after the ruler of the Bulgarian Khanate.