King George VI never expected to become the reigning monarch. However, he was next in line after his brother, Edward VIII abdicated. This rocked the United Kingdom and threatened the future of the monarchy. It also made Elizabeth the heir to the throne (via Express).
In this photo, Elizabeth and Philip stand beside the future queen’s parents. Notably, George wasn’t the King’s given name but the monarch could change it. Queen Victoria instructed that none of her descendants should eclipse her husband, Albert.