Judges 2:10
And also all that generation were gathered unto their fathers: and there arose another generation after them, which knew not the LORD, nor yet the works which he had done for Israel. And also all that generation were gathered unto their fathers: and there arose another generation after them, which knew not the LORD, nor yet the works which he had done for Israel.
The generation that was gathered to their fathers was Joshua's generation, including Joshua himself and the elders and rulers who outlived him. Those leaders had stood through their lifetime as steadfast sentinels for what was right and for God's honor. When they died there arose another generation after them which did not know the Lord and did not remember the works He had done for Israel.
That loss of knowledge and memory led directly to apostasy, for the people abandoned the Lord and turned to serve the gods of the surrounding nations. After those faithful leaders died God raised up righteous kings, and the history that follows runs from Joshua to David, from Rehoboam to the captivity, and from age to age until the Son of God came to call Israel back to allegiance. The same wicked purpose at work in that turning away was carried out again in the later determination of the Jewish people to have their own way by scheme after scheme and in their treatment of Christ.
The verse belongs to the account of revivals among God's ancient people. All who name the name of Christ should read it carefully and with an understanding heart. It is to be used to search their own hearts whether they are in the faith.