7 Year Old Adopted Dog Peeing Inside?

I have the most lovable Bulldog. I rescued him when he was 7 years old, I've had him for just over a year. I also have a hound mix; I've had her since she was 12 weeks old and she's now 5. The problem is my Bulldog will mark up my living room. He pees on the couch, on the entertainment center, and on the book shelf. It is like a constant circle in the living room. I'm so frustrated and not sure what to do. He will be great for a few days, then "bam", he marks it up again!

By Evelyn