Named drivers new insurance

Hi all basically my partner was a named driver on his brothers insurance as he used to help with school run whilst his brother worked away, anyway he was involved in a crash as a named driver and the other party as admitted full liability, as this has happened and the stress of not been named he has decided to get own car and own insurance and basically my question is does he need to declare on his new insurance as it was done through his brothers insurance. Hope this makes sense thank you