Duchy of Grand Fenwick in order

The Mouse That Roared & The Mouse on the Moon 2 films, 2h 48m in all, in release order.

The Mouse That Roared
1959 · 83 min
The Duchy of Grand Fenwick decides that the only way to get out of their economic woes is to declare war on the United States, lose and accept foreign aid. They send an invasion force (in chain mail, armed with bows and arrows) to New York and they arrive during a nuclear drill that has cleared the streets.
Popcorn Flick
The Mouse on the Moon
1963 · 85 min
Sequel to The Mouse that Roared; The Tiny Country of Grand Fenwick has a hot water problem in the castle. To get the money necessary to put in a new set of plumbing, they request foreign aid from the U.S. for Space Research. The Russians then send aid as well to show that they too are for the internationalization of space. While the grand Duke is dreaming of hot baths, their one scientist is slapping together a rocket. The U.S. and Soviets get wind of the impending launch and try and beat them to the moon.
New

Frequently asked questions

What order should I watch Duchy of Grand Fenwick in?

1. The Mouse That Roared (1959), 2. The Mouse on the Moon (1963).

How long does it take to watch all of Duchy of Grand Fenwick?

About 2h 48m across 2 released films.

Do any Duchy of Grand Fenwick films have post-credit scenes?

None are listed on TMDB.