The Duchess of Kent passed away at the age of 92 on September.
Her sad passing passing was announced on social media by the Royal Family’s official Twitter account.
For context, Duchess was the spouse of the late Queen Elizabeth II’s cousin, the Duke of Kent.
The Duchess’s coffin began its procession, travelling by hearse from her home at Kensington Palace to the Westminster Cathedral, where a private vigil is being held, including a Rite of Reception and Vespers for the Dead.
On Tuesday afternoon, September, 16, King Charles and Queen Camilla will join Prince Edward, Duke of Kent and members of Katherine’s family for the Requiem Mass.
The service will be conducted by the Cardinal Archbishop of Westminster.
Tuesday’s service will be unique in nature as it will be the first Catholic funeral for a Royal Family member in British history.
In 1994, the Duchess embraced the faith following a consultation with the late Queen, marking a significant change since 1700’s.
King Charles, as Supreme Governor of the Church of England, will attend the Catholic ceremony-a striking first in modern history.
Following the Mass, Katherine’s coffin will be taken to the Royal Burial Ground at Frogmore, Windsor, where she will be laid to rest.
The Duchess is survived by her husband, the Duke of Kent, aged, 89, as their three children, and ten grandchildren.