"This helped create a community made up of real people, but it also excluded a number of people who wanted to be part of it without using their real names."
Google has been loosening the requirement with changes such as letting people use YouTube account names, but conceded that the names policy got a bit muddled.
"Today, we are taking the last step: there are no more restrictions on what name you can use," Google said.
"We know you've been calling for this change for a while. We know that our names policy has been unclear, and this has led to some unnecessarily difficult experiences for some of our users.
"For this we apologize, and we hope that today's change is a step toward making Google+ the welcoming and inclusive place that we want it to be."