Pictured: Prince William runs for train to make it home for Kate'sbirthday celebrations
The royal couple are thought to have celebrated the Duchess of Cambridge's 32nd birthday privately at Kensington Palace
With a baseball cap pulled low and rucksack slung over his shoulder, he could have been any ordinary commuter dashing for his train.
But if the rush hour crowds in Cambridge yesterday had taken a closer look, they would have seen the man running for the 16.45 to Kings Cross was Prince William, rushing home to celebrate his wife's 32nd birthday.
But despite a schedule full of study and lectures, the second-in-line to the throne didn't want to miss Kate's birthday celebrations, and headed back to London to spend the evening with her and Prince George.
The couple are thought to have enjoyed a private dinner at Kensington Palace last night, after the Duchess spent her day looking after their five-month-old son.
There were no major celebrations to mark the occasion, and Kate has not been seen in public since Christmas Day.
But she is expected to appear at some public engagements while the Prince carries out his studies.
The couple will undertake their first royal tour with Prince George in April, when they travel to Australia and New Zealand.