The series first started out in 1996 on the original PlayStation and since then has grown into the biggest zombie-themed video game series of all-time. More than 80% of sales have come from outside of Japan.
This also makes it the first series in Capcom's history to reach and surpass this amount of sales. It's taken 24 years.
Nowadays, you can purchase most of the mainline Resident Evil games from the Switch eShop.