Gotta hand it to Murphy.
When Belle first got here, she lost little time in showing him that she was taking over. Some sparring and a couple of not-fooling-around dog fights established the new pecking order, or so you'd think. Murphy initially fell into line with his new Alpha female, but in true Murphy fashion, he soon started to peck away at her authority in small ways--cutting in front of her at the door, edging into the water bowl as she was drinking, standing up to her when she tried to take his toys...and eventually the relationship was redefined on an almost equal basis where she stopped trying to push him around and even deferred to him in some areas, such as when they're on the deck playing watchdog or when they're out walking on leash together with me. On leash, he takes lead dog position and she falls in at his shoulder. Belle was indisputably boss dog initially, but Murphy just kept challenging her incrementally and every time she let him get away with it, he just got bolder.
Now we're having daily sparring matches here in the Lair, where Murphy walks up to Belle and puts his head on her back--a dominant act of assertion over Belle, and while she ducks out from under when he does it, she's not correcting him. This morning, he was getting even brassier, going so far as to grab the back of her neck with his mouth. The first time he tried that when she was new here, she bit the hell out of him, but she's letting him do it now. It looks like Murphy's taking over as the Alpha dog in the house again and Belle's learning what I learned about Murphy a few years ago: He never stops trying, and if you give him an inch today, he'll be back for two inches tomorrow.
Good on ya, Murphy. Never give up, never surrender.