On July 28, the Orthodox Church celebrates the day of remembrance of the Holy Equal-to-the-Apostles Prince Vladimir and the 1033rd anniversary of the Baptism of Rus.Grand Duke Vladimir ruled Rus in the period from 978 to 1015. He stood at the origins of the adoption of Christianity in Russia. It was his will and state decision that determined the spiritual path, the direction of history and the development of culture.
The Holy Equal-to-the-Apostles Grand Duke Vladimir the Red Sun (960-1015) was the son of Prince Svyatoslav of Kyiv and the grandson of the Holy Equal-to-the-Apostles Grand Duchess Olga.
Historians call Volodymyr the Great, the Church calls him Saint Equal-to-the-Apostles, the people call him Volodymyr the Red Sun.
Source: https://www.calend.ru/holidays/0/0/2105/