1.
If something goes back to a particular time in the past, it was made or started at that time.
The feud with the Catholics goes back to the 11th century...
Our association with him goes back four years.
= date back
PHRASAL VERB : V P to n , V P n
2.
If someone goes back to a time in the past, they begin to discuss or consider events that happened at that time.
If you go back to 1960, you’ll find that very few jobs were being created.
PHRASAL VERB : V P to n , also V P n