M81 and M82 in Ursa Major were discovered by J.E.Bode in December 1774; M81 was recorded as a "nebulous patch, more or less round, with a dense nucleus in the middle". Messier added it to his catalogue in February 1781.
M81 is approximately 12 million light years distant. M82 is approximately 150,000 light years from M81 and is showing the effects of a catastrophic encounter with M81 some tens of millions of years ago.
Note a very faint companion galaxy (UGC 5336) below the image of M81 (similar to Large Magellanic Cloud associated with our galaxy).