The line had previously announced the addition of the two ships late last year.
Neil Barclay, head of sales U.K., reiterated to Cruise Critic that the decision to build the new ships is a direct result of the success of the line's first ship, debuting next year.
"Our maiden season in 2015 is already nearly at capacity," he said.
The ships will sail similar Scandinavia, Baltic and Mediterranean itineraries as Viking Star, but will also do two new British Isles and Northern Europe journeys.
Viking Cruises recently made history (again) with the simultaneous christening of 16 new river ships.
--By Dori Saltzman, News Editor