Identical twins Florence Davies and Glenys Thomas were born five minutes apart on November 22 1911 - the year of King George V's coronation.
The inseparable pair spent most of their adult lives living next door to each other in Abertridwr, Wales, and between them they now have five children, 12 grandchildren and 19 great-grandchildren.
A spokesman at Abermill Care Home in Caerphilly, South Wales, where the sisters now live, told local news website Wales Online: "They even built an interior door joining their two kitchens to make it even easier for them to see each other."
At Abermill, Glenys and Florence now have rooms a couple of doors away from each other and enjoy spending time together in the communal lounge area.
Care Home manager, John Roberts, said the home researched twins in Britain and discovered that Florence and Glenys had inherited the title of the UK's oldest earlier this month when they celebrated their 103rd birthdays together along with their family, friends, fellow residents and staff.
"Florence and Glenys have achieved a truly remarkable feat," said John.
"It is so lovely to see them celebrate this milestone together and with their family and friends, we're thrilled to be part of it.
"Also, a big thank you goes to everyone who made Florence and Glenys' 103rd birthday so special, and to the kitchen staff for providing such a great spread of food – it really was a special day."
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