After isolating for months at Windsor Castle, Queen Elizabeth II and Prince Philip have flown off to Scotland to enjoy summer holiday with the rest of the British royal family.

The royal couple, who has been isolating at the Windsor Castle since the outbreak of COVID-19 illness in March, ended four months of lockdown by flying to Scotland for their summer holiday. They were spotted sitting side by side in a car driven from Windsor to RAF Northolt in London on Tuesday afternoon, reports The Sun.

For the trip, the queen wore a light blue jacket with pearls paired with her signature black handbag, while the Duke of Edinburgh sported a collared shirt under a green jumper. They then boarded a private jet heading to the Balmoral estate, where they are expected to stay until at least September. One of the queen's pet dogs was also seen being carried off the plane when it arrived in Scotland.

The British royal family usually spends their summer holidays at the Balmoral estate in Scotland doing a variety of activities including picnic, horse-riding, and hunting. The tradition to come together at the 50,000-acre estate in Aberdeenshire for 12-weeks has been followed for each of the past 68 years of Queen Elizabeth II's reign.

However, the plans were in limbo this year because of the coronavirus pandemic, and there were even speculations of the holiday being cancelled. It was later revealed that the British monarch will be joined by her family in Scotland, but she and Prince Philip will be practising social distancing and living in separate buildings than other members as they fall in the high-risk group for the virus at the age of 94 and 99, respectively.

Queen 90th birthday
1974: The Queen arrives at Aberdeen airport with her corgis to start her holidays in Balmoral. Her handbag by British brand Launer and handmade shoes by Anello and Davide of Kensington have remained the same style for over 50 years, whilst more contemporary additions such as the feather headpiece are typically 1970's. Anwar Hussein/Getty Images

It is also said that the couple will be joined by a small team of key staff being called "Balmoral Bubble," which will look after them during their stay at the estate. While their eldest son Prince Charles has already arrived in Scotland with wife Duchess Camilla, the rest of the family is also expected to join them in the coming days.