After Israel rebelled, which tribe alone followed the house of David?

Answer: Judah

When Jeroboam was made king over all Israel, only the tribe of Judah followed the house of David.

“When all Israel heard that Jeroboam had returned, they summoned him to the assembly and made him king over all Israel. Only the tribe of Judah followed the house of David.”— 1 Kings 12:20 (BSB)