Andrei Kobyla was documented in contemporary Russian chronicles only once, in 1347,[1][2] when he was sent by Simeon of Moscow to Tver with the purpose of meeting Simeon's bride, who was a daughter of Aleksandr Mikhailovich of Tver.

They first claimed that he had arrived in Moscow in 1341 from Prussia,[3] where his father, Glanda Kambila, was a famous Prussian holdout against the conquest of Balts by the Teutonic knights.

[citation needed] In the late 17th century, after the Romanov's elevation to Russia's ruling dynasty, this origin story was replaced by a more grandiose lineage.

A fictional line giving Andrei Kobyla's descent from Julius Caesar was published.

16th-century genealogies mention five of Andrei's sons: Simeon Zherebets, Alexander Yolka, Vasily Vantey, Gavrila Gavsha, and Fyodor Koshka.