cat is named "Britain". She has loved all things British (and Irish and Scottish) since before I can remember. She went on a study-abroad to London when she was in university. In the past several years she has received several Union Jack gifts from me, including a hand-knit pillow and tea pot cover. I also have purchased British items whenever I find ones that look that they fit her.
When I found out she was getting married and we needed to plan a wedding shower, a British theme sounded perfect. Initially, I was thinking a Downton Abbey themed shower. Then I found out one of the bridesmaids had never even seen the series. I saw several nice customizable invitations with Union Jacks on Etsy, but now only were we trying to do a cute shower, we were also trying to keep the costs down.
For games, one of the bridesmaids found a Downton Abbey game, but we ended up saving that as a "reserve game" in case we had down time. The game that the bridesmaid created of British-American slang words was a fun one for everyone to do. The bridesmaid also found perfect pens with the Union Jack on then (apparently she got these imported from England, and through a mix-up she ended up getting 100 of them and even a display stand but that's another story).
For decorations, we were fairly simple, red, white and blue ribbons and balloons, Union Jack cocktail napkins and little telephone booth boxes that I found on Amazon. Inside the boxes were hand-made chocolates from some future family members.
My mom contributed a lot with little "London toy buildings" and British prizes. The shower took place at a great little tea room with wonderful food and everyone had a good time. A success overall!