Take this painting for example. This is Tristam and Fox by Gainsborough. All of London society was paying hundreds of thousands of dollars (in today's terms obviously) to be painted by Gainsborough, this one was on the house. Not only that but it was this painting that was placed in the coveted spot above the mantel. These were Gainsborough's dogs, Fox (center) and Tristam (right) were honored members of the family. Whenever Gainsborough and his wife fought, he would apologize in a letter signed, "Fox" and Fox himself would deliver the letter into Mrs Gainsborough's hands. How adorable is that! I might just have a crush on him, even if he is a dirty Tory.
Speaking of Tories, Fox was named after Charles James Fox, the infamous Whig politician who Georgiana canvassed for in 1784. Given that Gainsborough probably hated Charles Fox's guts it was a name given in humor. Tristam was more literary, he was named after the hero from The Life and Opinions of Tristam Shandy, Gentleman by Laurence Sterne. Based on the title of that book I think thats a great dog name too. My dog is named after Luke Skywalker.