1 Kings 12:20

And it came to pass, when all Israel heard that Jeroboam was
come again
Out of Egypt; the chief men knew of it before, for he had headed them in their approach and address to Rehoboam; but the people in common had not, and especially those of the various tribes besides that of Ephraim:

that they sent and called him unto the congregation, and made him king
over all Israel;
they sent for him from his tent or house, which probably was in Shechem, and gave him an invitation to come to their assembly, met together to deliberate about a king; when they unanimously chose him to be king over Israel, that is, over the ten tribes, and inaugurated him into his office:

there was none that followed the house of David but the tribe of Judah
only;
in which Benjamin was included, as appears from the following verse; that being joined to it, and mixed with it, and both having a part in Jerusalem, and so ever after the kingdom was denominated the kingdom of Judah.