Kensington Palace announced that Kate was "making good progress" and has returned home to Windsor to continue her recovery following the stint in hospital.
In a statement, the palace said: "The Prince and princess with to say a huge thank you to the entire team at The London Clinic, especially the dedicated nursing staff, for the care they have provided."
Kate's health scare came as Buckingham Palace revealed King Charles was preparing for a corrective procedure after being diagnosed with a benign enlarged prostate. Charles, who acceded to the throne 16 months ago, was admitted to hospital on Friday and is said to be "doing well".
Here's a breakdown of what we know - and don't know - about the Princess of Wales's surgery:
What we know
An initial statement released by Kensington Palace revealed that Kate was admitted to the private London Clinic on 17 January. The palace has since said that the planned procedure was successful. She stayed in hospital for 12 days before returning to her Adelaide Cottage home in Windsor.
A statement also said the princess is not expected to return to public duties until after Easter based on current medical advice.
William took time off and stepped back from all official duties for several weeks while he looked after their three children - Prince George, Princess Charlotte and Prince Louis - and helped care for his wife.
Kate is now expected to miss several upcoming engagements as the statement said she is “unlikely” to return to public duties “until after Easter”. With Easter weekend falling at the end of March, that means she is out of action until at least April.
Events that she usually attends, and will now probably miss, include the Baftas in February, the Six Nations tournament that runs from February to March, St David’s Day on 1 March, the Commonwealth Day service on 11 March and the Easter Sunday Service.
That also means there will be no international travel for her for the foreseeable future - trips to Latvia and Rome, believed to take place in the spring, are in jeopardy.
We also know that further details of Kate’s medical information will remain private for the foreseeable future. Kensington Palace said her progress will only be shared “when there is significant new information”.
Kate and King Charles's absence from public life (plus William's decision to step away) means the King's "slimmed-down" monarchy is somewhat exposed. However, the counsellors of state – senior royals who are authorised to carry out official duties on behalf of the sovereign – will not be needed while the King undergoes surgery, according to Buckingham Palace.
The double health scare is, however, an indication of how fragile Charles's approach to the monarchy is - particularly as two royals, Prince Harry and the Duke of York, do not carry out official duties.
What we don’t know
Beyond describing the surgery as "successful", the initial palace statement gave no indication as to the serious of the surgery and the impact it has had on Kate. The most recent statement did not give any further details on the type of surgery she underwent.
While the statement said that Kate would “likely” not be returning to public duties until after Easter, the precise timing of that is still not known. April is the earliest date, but it could be that Kate cancels more engagements beyond then. The Times reports that her diary has been cleared for “many months”.
Reports in The Daily Mail suggest that Kate is likely to be advised to recover for two to three months. They add that any return to official duties would entirely depend on the medical advice she receives closer to the time.
And while Kensington Palace said the surgery was “planned”, we don’t know how long it had been planned - though it does likely mean the surgery was not an emergency procedure. The paper also suggests what the surgery might have entailed – including for gallstones, an appendectomy or to repair a hernia. According to the well-connected Royal Central website, the Palace reportedly told journalists that her condition was not cancerous.
Despite these suggestions, we don’t – and may never – have the details of what the operation was for, with the statement saying that Kate’s medical notes are private.