[1] It is most commonly used in Russia, Belarus, Ukraine, Bulgaria, Serbia, Bosnia and Herzegovina, Croatia, North Macedonia, Montenegro, Slovakia, Slovenia and other countries in Eastern Europe.

[2][3] It can be used as a short form of the name Borislav, derived from the Slavic elements borti "battle" and slava "glory", "fame".

Moreover, after his death in AD 907 he was proclaimed the first Bulgarian saint, and traces of his Orthodox sainthood during this period can be found as far away as Catholic Ireland.

As evidenced by the Rus' Primary Chronicle, Boris and Gleb were sons of Vladimir I, born to him by the Bulgarian princess.

[11] In 1015, the princes Boris and Gleb were killed by their stepbrother Sviatopolk I of Kiev, who usurped the throne.

Within a short time, Boris and Gleb were canonized and ever since, they have been the native soldier-saints most revered among the Ukrainians, Russians and Belarusians.