The Queen said private prayers for her beloved Duke of Edinburgh as she attended a Sunday mass in Windsor Castle.
The monarch, who is head of the Church of England, has a deep Christian faith and will be drawing on this in her time of grief.
The mass was also not in St George’s Chapel, which is currently closed and is where Philip’s funeral will take place on Saturday.
Philip and the monarch’s second son the Duke of York has told of the depth of his mother’s feelings, saying she described the death of her husband of 73 years as “having left a huge void in her life”.
The Queen, who takes her Christianity seriously as Supreme Governor of the Church of England, usually attends church each Sunday.
Each year, she delivers her televised Christmas message, incorporating a strong religious theme.
Following the duke’s death at the age of 99 on Friday, the Archbishop of Canterbury led tributes from faith leaders, describing Philip as an “outstanding example of Christian service”.