As the second World War raged, then-Princess Elizabeth rallied to the cause and enlisted in the military, helping boost the morale of the British people.

One of the most famous figures in medical history, the nurse's groundbreaking achievements in handwashing, hygiene and sanitation helped revolutionize medicine.

For centuries, generations of royals have endured many ups and downs with their children.

The Italian dictator described "The Cardinal's Mistress" as “a novel for seamstresses and scandal.”

The writer helped the former president develop his best-selling memoirs before Grant's 1885 death.

The French Revolution tore the queen apart from her two surviving offspring.

Many believe the former British king lived an erratic existence due to ongoing, and sometimes undiscovered, health issues.

The musician's fluctuating financial status led many to believe he died a pauper.

'Ever thine. Ever mine. Ever ours.' Two centuries later, historians still haven't agreed on the identity of the woman who inspired the composer's famed lines.

Theories suggest the writer did not compose his famous works like 'Hamlet' and 'Julius Caesar.'

Having a friendly relationship with Adolf Hitler, many speculated that the Duke and Duchess of Windsor were involved in a plot to overthrow the British crown during World War II.

Stemming from her own difficult childhood, the British queen and her nine offspring experienced tension and dysfunction from the moment they were born.

After Lee's 'To Kill a Mockingbird' became a best-seller, Capote competed to keep up, eventually putting a wedge between the writers.

The accused killer began living lavishly, only to have the residents of Fall River, including her sister, ice her out.

The 39th president and former first lady have been a couple for more than 70 years.

Branded a "sick comic," the stand-up pushed boundaries with his foul-mouthed routines, which led to his 1964 arrest.

Required to perform safe and clean routines in front of primarily white audiences, the comedian had enough of club owners telling him what to do.

The 'Tonight Show' host declared that the comedienne would be a star, but two decades later, the friends would stop speaking to each other forever.

The personal contents were placed in a box and weren't revealed until more than 100 years after the president's assassination.

Despite JFK's father feuding with the Prime Minister during World War II, the late president idolized and took cues from the British politician.

The Prime Minister was rarely spotted without his favorite accessory — a cigar.

The Nobel Prize winner retreated to the Florida island in the 1920s and ultimately discovered a new muse — the city itself.

The scientist's discoveries and theories laid the foundation for modern physics and astronomy.

It lasted just seconds, but the brief interaction between JFK and Bill Clinton inspired the teen to a life of public service — and helped lead to his own election as president 30 years later.