Your FICO score is the first thing a mortgage lender will check when seeing if you qualify for a loan. While there are many factors involved in qualifying for a loan, your credit score is the most important.
The minimum credit score you need to purchase a home will depend on the type of home loan you qualify for.
Before the 2007-2008 housing market crash, it was much easier for people with poor credit to find subprime loans. Lenders were not as heavily regulated as they are today.