in British television – A series of US-style head-to-head party leaders' debates are broadcast across UK television ahead of the 2010 general election, the first such debates to be held in the run up to a UK election. ITV's breakfast television service GMTV is axed after seventeen years on air, and replaced by Daybreak. Coronation Street celebrates its 50th year on air with a live episode, while EastEnders marks its 25th anniversary. The ITV period drama Downton Abbey makes its television debut. 2011 in British television – Viewers watch the Wedding of Prince William and Catherine Middleton, and the first broadcast of Mrs. Brown's Boys on BBC One. Little Mix become the first group to win The X Factor. BBC Four begins rerunning old editions of Top of the Pops on Thursday evenings, starting from April 1976. 2012 in British television – Spring of this year sees The Weakest Link come to an end with the 1,693rd edition, when Anne Robinson retires from the show to concentrate on Brand newer series of Watchdog, CBeebies celebrates 10 years of being separated from CBBC, Spring 2012 also sees Harry Hill's TV Burp ending on ITV with a huge finale after 10 or 11 years of broadcast, as well as the Teletubbies celebrating their 15th actual anniversary on the BBC. The events of the Olympic Games begin airing with the opening ceremony in London as well as the debut of Tipping Point from July of this year. The Digital Switchover is completed in October as the final analogue transmitters are switched off in Northern Ireland. In Scotland, the sentencing phase of the trial of David Gilroy is the first in the United Kingdom to be filmed for broadcast. 2013 in British television – BBC Two launches in high-definition for the first time years after BBC One did, Panorama becomes the first ongoing British TV programme to reach and celebrate its 60th anniversary since BBC Wimbledon in 1987 The Boat Race in 1998 and BBC Cricket in 1999, More4 also launches in HD for the first time, CITV will celebrate its 30th anniversary by airing an Old Skool weekend and Doctor Who celebrates its 50th anniversary by airing a special episode all across both Britain and the globe. Spring 2013 also sees the BBC Television centre's old building close with all the BBC services in London moving to the new one next door known