Precession.

The CNP  is 'the celestial north pole'. 
If you were at the North pole the CNP would be at the zenith.
If you were at the equator, the CNP would be on the horizon.

Latitude (the elevation angle, from the horizon to the CNP) does not change with precession.

A star close to the pole position is a 'pole star'.

The pole star changes over time.

Because the CNP remains at the same angle, but rotates slowly, pointing to different stars..

 There is a gradual shift in the orientation of Earth's axis of rotation

 The time taken for one rotation is a Great Year

 26,000 years

This image of the constellations shows the effect of procession on the night sky.

Precession changes longitude not latitude.

The black stars in this diagram are in their current position.

The open stars show the position 2,000 years ago.

Precession changes the star's position by about 1 degree every 70 years.

2,000 years =  2000 / 70 = 28 degrees change.

The position of the stars change in relation to the equator.

The position of the stars remain the same in relation to the ecliptic.

So a star 2,000 years ago will have the same latitude as today, but its longitude is set back by 28 degrees.