The Independent's Jack de Menezes stated earlier in the day that the two clubs had agreed a fee in the region of £9 million, which enabled the 21-year-old to travel to the Welsh capital to undergo a medical. Caulker came through the test without a hitch and promptly signed a four-year contract.
Tottenham have problems in defence, with Jan Vertonghen picking up an injury in a preseason friendly last week.
Vertonghen slipped on a wet pitch and damaged ankle ligaments in an Asia Cup game with Sunderland. Spurs boss Andre Villas-Boas confirmed, via skysports.com, that Vertonghen would be sidelined for three weeks, but he was happy to allow Caulker to move on.
Speaking to Cardiff's official website, Caulker said:
“I spoke to the gaffer yesterday, liked what he had to say and am excited about the plans he has for the football club. You get the sense of excitement from everybody at the club in the build-up to the season’s kick-off at West Ham and I’m really looking forward to being part of it.
“I thank Tottenham for everything they’ve done for me, having been there since I was a kid. But I’m here to back myself up now and show what I can do. This is a fresh start, a new chapter and I’m here to kick on.”
Since securing promotion to the Premier League in May, Cardiff boss Malky Mackay has been busy in the transfer market.
Wales Online is reporting that the fee for Caulker would eclipse the £8.5 million shelled out for Cornelius and make him the club’s record transfer.
Caulker came through the Tottenham youth system and made his professional debut in 2009, while on loan at Yeovil, according to Soccerbase. He has had loan spells at Yeovil and Bristol City, as well as a stint at Swansea in the 2011/2012 campaign.
He has one England cap to his name and he marked his debut against Sweden in a friendly in November 2012 with a goal. England lost the game in Solna 4-2.