Volga Delta in the context of "Khanate of Astrakhan"

The Danube Delta (Romanian: Delta Dunării, pronounced [ˈdelta ˈdunərij] ; Ukrainian: Дельта Дунаю, romanized: Del'ta Dunaju, pronounced [delʲˈtɑ dʊnɐˈju]) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. Occurring where the Danube River empties into the Black Sea, most of the Danube Delta lies in Romania (Tulcea County), with a small part located in Ukraine (Odesa Oblast). Its approximate surface area is 4,152 square kilometres (1,603 square miles), of which 3,446 km (1,331 sq mi) is in Romania. With the lagoons of Razim–Sinoe (1,015 km or 392 sq mi with 865 km or 334 sq mi water surface), located south of the main delta, the total area of the Danube Delta is 5,165 km (1,994 sq mi). The Razim–Sinoe lagoon complex is geologically and ecologically related to the delta proper; the combined territory is listed as a World Heritage Site.

The Caspian expeditions of the Rus' were military raids undertaken by the Rus' between the late 9th century and c. 1041 on the Caspian Sea shores, of what are nowadays Iran, Dagestan, and Azerbaijan. Initially, the Rus' appeared in Serkland in the 9th century travelling as merchants along the Volga trade route, selling furs, honey, and slaves. The first small-scale Viking raids took place in the late 9th and early 10th century. The Rus' undertook the first large-scale expedition in 913; having arrived on 500 ships, they pillaged in the Gorgan region, in the territory of present-day Iran, and more to the west, in Gilan and Mazandaran, taking slaves and goods. On their return, the northern raiders were attacked and defeated by the Khazars in the Volga Delta, and those who escaped were killed by the local tribes in the middle Volga.

During their next expedition in 943, the Rus' captured Bardha'a, the capital of Arran, in the modern-day Republic of Azerbaijan. The Rus' stayed there for several months, killing many inhabitants of the city and amassing substantial plunder. It was only an outbreak of dysentery among the Rus' that forced them to depart with their spoils. Sviatoslav, prince of Kiev, commanded the next attack, which destroyed the Khazar state in 965. Sviatoslav's campaign established the Rus's hold on the north-south trade routes, helping to alter the demographics of the region. Raids continued through the time period with the last Scandinavian attempt to reestablish the route to the Caspian Sea taking place in c. 1041 by Ingvar the Far-Travelled.

45°2′N 38°58′E / 45.033°N 38.967°E / 45.033; 38.967

Kuban (Russian and Ukrainian: Кубань; Adyghe: Пшызэ; Kabardian: Псыжь; Karachay-Balkar: Къобан; Nogai: Кобан; Abaza: Къвбина) is a historical and geographical region of southern Russia surrounding the Kuban River, on the Black Sea between the Don Steppe, the Volga Delta and separated from the Crimean Peninsula to the west by the Kerch Strait. Krasnodar Krai is often referred to as Kuban, both officially and unofficially, although the term is not exclusive to the krai and also accommodates the republics of Adygea, Karachay-Cherkessia, and parts of Stavropol Krai.

Astrakhan (Russian: Астрахань, IPA: [ˈastrəxənʲ] ) is the largest city and administrative centre of Astrakhan Oblast in southern Russia. The city lies on two banks of the Volga, in the upper part of the Volga Delta, on eleven islands of the Caspian Depression, 100 km (62 mi) from the Caspian Sea, with a population of 475,629 residents at the 2021 Census. At an elevation of 28 meters (92 ft) below sea level, it is the lowest city in Russia.

Astrakhan was formerly the capital of the Khanate of Astrakhan (a remnant of the Golden Horde) of the Astrakhan Tatars, and was located on the higher right bank of the Volga, eleven kilometres (6.8 mi) from the present-day city. Situated on caravan and water routes, it developed from a village into a large trading centre, before being conquered by Timur in 1395 and captured by Ivan the Terrible in 1556 and in 1558 it was moved to its present site.

Sturgeon is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are descended from other, earlier acipenseriform fish, which date back to the Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into five genera: Acipenser, Huso, Scaphirhynchus, Sinosturio, and Pseudoscaphirhynchus. Two species (H. naccarii and S. dabryanus) may be extinct in the wild, and one (P. fedtschenkoi) may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. A Maastrichtian-age fossil found in Morocco shows that they also once lived in northern Africa during the Cretaceous.

Sturgeons are long-lived, late-maturing fishes with distinctive characteristics, such as a heterocercal caudal fin similar to those of sharks, and an elongated, spindle-like body that is smooth-skinned, scaleless, and armored with five lateral rows of bony plates called scutes. Several species can grow quite large, typically ranging 2–3.5 m (7–12 ft) in length. The largest sturgeon on record was a beluga female captured in the Volga Delta in 1827, measuring 7.2 m (23 ft 7 in) long and weighing 1,571 kg (3,463 lb). Most sturgeons are anadromous bottom-feeders, migrating upstream to spawn but spending most of their lives feeding in river deltas and estuaries. Some species inhabit freshwater environments exclusively, while others primarily inhabit marine environments near coastal areas, and are known to venture into open ocean.