Favilla, like Martin, were a mainland US guitar company who were quick to pick up on the trend for ukuleles in the 1920s. They carried on making ukuleles up until 1968 (and baritones up to 1985) but most Favilla ukuleles are from the 1920s and 30s.
Favilla's most famous ukulele design is the tear-shaped uke - which looks a great deal like a mandolin (inspired no doubt by the Favilla family's Italian heritage).
Although their ukuleles don't fetch quite the prices of Martin ukuleles, they are quickly rising in price (particularly the older ukuleles).
There's a history of the Favilla company as a whole here.