Currently, Earth’s pole stars are Polaris (Alpha Ursae Minoris), a magnitude 2 star aligned approximately with its northern axis, and a pre-eminent star in celestial navigation, and Polaris Australis (Sigma Octantis), a much dimmer star. A couple thousand years ago, Kochab and Pherkad were twin northern pole stars, though neither was as close to the pole as Polaris is now. […]
In the medieval period, Polaris was also known as stella maris “star of the sea” (from its use for navigation at sea) […] Polaris was associated with Marian veneration from an early time, Our Lady, Star of the Sea being a title of the Blessed Virgin. […]
During the 1st millennium BC, Beta Ursae Minoris (“Kochab”) was the bright star closest to the celestial pole, but it was never close enough to be taken as marking the pole, and the Greek navigator Pytheas in ca. 320 BC described the celestial pole as devoid of stars. In the Roman era, the celestial pole was about equally distant between Polaris and Kochab.
Source: Pole star – Wikipedia