This year's birthday will be overshadowed by the death of Prince Philip, her husband of 73 years.
Queen Elizabeth II turns 95 on Wednesday, less than two weeks after her husband of 73 years, Prince Philip, passed away.
The queen's loss was underscored by Saturday’s funeral at St. George’s Chapel on the grounds of Windsor Castle, where the figure of a widow in black sitting alone offered a glimpse of the next solitary phase of her reign.
For now, the longest-serving monarch in British history continues to reign. But she will do so without Philip, the man the queen called her “strength and stay,” a source of emotional support in her often lonely job.
British Prime Minister Boris Johnson sent "warm wishes" to the monarch on her birthday. "I have always had the highest admiration for Her Majesty and her service to this country and the Commonwealth."
"I am proud to serve as her Prime Minister," he added on Twitter.
Elizabeth was formally crowned on June 2, 1953, at the age of just 25 after her father George VI died suddenly in 1952.
During that ceremony, televised around the world, the queen promised to govern the United Kingdom and her other realms. Six years earlier, in a speech in South Africa, then-Princess Elizabeth made clear that her commitment was for life.
“I declare before you all that my whole life, whether it be long or short, shall be devoted to your service and the service of our great imperial family to which we all belong,” she said.
With a reign that has so far lasted almost seven decades, Elizabeth has seen governments rise and fall, entertained generation after generation of heads of state, and presided over a family with its own share of tragedy and controversy.
A then-Princess met her future husband, her distant cousin Philip from the Greek royal family, during a royal visit to Dartmouth Naval College in 1939.
Their engagement came on her 21st birthday in April 1947.
That same year, on November 20, she and Philip were married in a massive ceremony, a colourful event which made worldwide headlines in the drab years following the Second World War.
Elizabeth and Philip raised four children: Prince Charles, Princess Anne, Prince Andrew and Prince Edward.
With the United Kingdom reminded that the reign of the queen, the only monarch most of her subjects have ever known, is finite, speculation has been triggered about how long she will remain on the throne, what the monarchy will look like in the future and, for some, even whether it should continue to exist.
While most observers say the queen is unlikely to abdicate given her lifelong commitment to public service, she has already started to turn over more responsibilities to Prince Charles, 72, her eldest son. That process is likely to accelerate following Philip’s death.
While her popular grandson, Prince Harry, has stepped away from royal duties, the rest of the royals, backed by professional staff and advisers, are likely to rally around the queen and take on more tasks.
Sustaining the institution will be the bedrock popularity of the Duke and Duchess of Cambridge, who have a reliable ability to connect with the public.