Find Out How Queen Elizabeth II and Prince Phillip Are Preparing For When Death Parts Them 

Queen Elizabeth fell head-over-heels for Prince Philip when she was just a teen, and now they are celebrating 70 years together!

for an inside look into their untold love story – only in PEOPLE!

As they gather to mark the 70th wedding anniversary of Queen Elizabeth and Prince Philip at Windsor Castle on Nov. 20, the royal family will toast the latest amazing milestone in a lifetime of records.

But the celebration will be tinged with some sadness at those who can’t be there alongside the Queen, 91, and Philip, 96. With the long march of years, many of their friends are no longer with them: The Queen lost her cousin and confidante Margaret Rhodes a year ago and one of her bridesmaids Lady Elizabeth Longman soon afterward, and the royal couple are keenly aware of their advancing years.

However, insiders say they are prepared for their inevitable parting. A former staffer plays up the strong faith that underpins their life, telling PEOPLE in the latest issue, “They will be stiff upper lip in public and keep their own emotions behind it,” a former staffer tells PEOPLE in this week’s cover story, emphasizing the strong faith that underpins their life together. “They are both deeply religious people and it won’t take them by surprise.”

Queen Elizabeth and Prince Philip at the Broadlands estate in 2007.

The couple, who wed in Westminster Abbey in 1947  “are both resilient characters,” says royal historian Robert Lacey, who penned the official companion of Netflix’s hit series 

. “Their life together has always been built on regular separations. They are not a soppy couple.”

1 Prince Harry Jokes That He ‘Can’t Hide’ Meghan Markle at Public Events

2 Prince William Honors Veterans at Gala Dinner — the Story Behind His Poppy Pin

3 Queen Elizabeth Jokes About Her Mortality in New TV Documentary

4 Prince Harry Salutes Fallen Service Members at Westminster Abbey Field of Remembrance Ceremony

5 Prince Rainier Did the Dishes at Grace Kelly’s House Before They Married