Just like for the preceding Golden Horde, the main source of revenue of the Great Horde was collecting transit fees and
customs duties from the commercial traffic along the lower Volga river. The khans at Sarai controlled a decreasing number of tributary vassals from previous centuries, losing the southwestern Rus' (Ruthenian) principalities to the
Grand Duchy of Lithuania, and in the 1470s its traditional ally in the north, Muscovy, refusing to pay tribute any longer. By the second half of the 15th century, the Great Horde found itself unable to properly control and protect trade on the lower Volga anymore either. Tverian merchant
Afanasy Nikitin recounted in his famous travelogue
A Journey Beyond the Three Seas how he had no troubles sailing the Volga downstream from
Tver in 1466–1468, until his group of merchants was attacked and robbed by bandits near
Astrakhan. Returning from Persia, Venetian diplomat
Ambrogio Contarini had his property confiscated at Astrakhan when he passed through in 1475–1476; he was compelled to pay a large ransom to get it back. Contarini described 'the country between [Astrakhan] and Muscovy... [as] a continual desert.' There were no
way stations, no places to buy provisions, and fresh water was hard to come by. He spotted some camels and horses that were apparently abandoned or lost by a previous caravan that presumably had suffered an ill fate as well. Ahmad Khan made it a policy to raid merchant caravans carrying valuable goods across his territory, in order to make up for these losses in revenue, but thus destabilising commerce in the region even further. Moreover, the Great Horde raided the territory of its neighbouring states for extra spoils, including the Oka river border with its nominal vassal Muscovy from the late 1440s onwards. A 1460 attack on Ryazan by the Sarai khan served the same purpose. In 1472, by which time Ahmad Khan was allied with Lithuania, which urged him to raid territory of their mutual Muscovite enemy, the Great Horde burnt down the town of
Aleksin and crossed the Oka, but was then repelled. ==Khans of the Great Horde==