The Queen and the Duke of Edinburgh, are set to celebrate their 65th wedding anniversary.
The couple will join around 2,000 other British couples in celebrating their Blue Sapphire wedding anniversary this year, but have mentioned no plans for a major celebration yet.
After attending the Royal Variety Performance in London on Monday, the Queen and the Duke will spend a quiet day together on Tuesday before carrying on with their duties for the rest of the week, including a joint visit to Bristol on Thursday and official engagements for the Duke tomorrow and on Friday, The Telegraph reports.
According to the paper, a spokesman for the Queen said the couple would be "marking the day privately".
The Queen had first met the then Prince Philip in 1939, when she was just 13 and he was a naval cadet.
He had reportedly played croquet with his future bride, who became his pen-pal during the war. The couple married at Westminster Abbey in 1947, the paper said.