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Wikipedia dicit:

Thuban, designation Alpha Draconis (α Draconis, abbreviated Alpha Dra, α Dra), is a star (or star system) in the constellation of Draco. A relatively inconspicuous star in the night sky of the Northern Hemisphere, it is historically significant as having been the north pole star from the 4th to 2nd millennium BCE. Even though Johann Bayer gave Thuban the designation Alpha, its apparent magnitude of 3.65 means it is 3.7 times fainter than the brightest star in the constellation, Gamma Draconis (Eltanin), whose apparent magnitude is 2.24.

Due to the precession of Earth’s rotational axis, Thuban was the naked-eye star closest to the north pole from 3942 BCE, when it superseded Iota Draconis as the Pole Star, until 1793 BCE, when it was superseded by Kappa Draconis. It was closest to the pole in 2830 BCE, when it was less than ten arc-minutes away from the pole. It remained within one degree of celestial north for nearly 200 years afterwards, and even 900 years after its closest approach, was just five degrees off the pole. Thuban was considered the pole star until about 1800 BCE, when the much brighter Beta Ursae Minoris (Kochab) began to approach the pole as well.

Having gradually drifted away from the pole over the last 4,800 years, Thuban is now seen in the night sky at a declination of 64° 20′ 45.6″, RA 14h 04m 33.58s. After moving nearly 47 degrees off the pole by 10000 CE, Thuban will gradually move back toward the north celestial pole. In 20346 CE, it will again be the pole star, that year reaching a maximum declination of 88° 43′ 17.3″, at right ascension 19h 08m 54.17s.

Video credit: NASA/ Chris Smith (USRA): Lead Producer/Chris Smith (USRA): Lead Animator/Francis Reddy (University of Maryland College Park): Lead Science Writer