Narrowing down the wealth of quality players in the home unions to just 37 was never going to be an easy task - and it is understandable that the decisions went right to the wire.
There were some tough calls across the squad - and as a result a number of class players missed out on selection.
And following the confirmation of the Class on 2013, we look at team of players unlucky to miss out...
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15 Mike Brown (England)
The Harlequins ace has been in sensational form for club and country and has shown his versatility, too. Brown played out of position for England on the wing during the RBS Six Nations, however he put in some impressive shifts. In his preferred No 15 jersey for Quins, Brown has continually been the standout performer - he is safe under the high ball, aggressive in defence and has worked hard to add a useful turn of pace to his repertoire.
14 Simon Zebo (Ireland)
The Irishman showed some nice touches during the RBS Six Nations - with some nifty footballing skills leading to a try against Wales - however injury struck at the wrong time. The Munsterman made a timely return to action but he has failed to convince Warren Gatland he is worth the risk. The 23-year-old has scored 20 tries in 48 appearances for Munster - including a hat-trick against Racing Metro in the Heineken Cup this season.
13 Matt Scott (Scotland)
According to the stats Scott was the only Scotland international to make the RBS Six Nations Team of the Championship, but he failed to make the 37-man squad for the Lions. Scott was 'Mr Consistent' for Scotland, hardly putting a foot wrong and even showing plenty of nice touches in attack. However, Scott's misfortunate is that it was always going to take a miracle to break into the Lions midfield.
12 Ian Madigan (Ireland)
If Gatland had been looking for someone in the back division to add some X-Factor then Madigan would have fitted the bill. The Leinster back has enjoyed a standout season, with his form earning him a place in the RaboDirect PRO12 Dream Team as well as his club's Players' Player of the year title. In 29 appearances this season Madigan has weighed in with 228 points, with his elusive running resulting in eight tries.
11 Christian Wade (England)
Another uncapped player whose stellar domestic form saw him considered for the trip to Australia. Wade has proved there is more to wing play than the modern-day belief you need a big unit out wide. His tally of 18 tries in 26 appearances have been crucial to Wasps this season - with Wade's electric pace, quick feet and low centre of gravity tormenting defenders this season.
10 Jonny Wilkinson (England)
The World Cup-winning fly-half had the chance to tour with the Lions, however, Wilkinson opted to turn down the offer. The 33-year-old claimed his fitness and commitments with Toulon meant it was best for him to miss out. His performances in the Top 14 and the Heineken Cup proved he is still among the world's best - with his kicking, game management and defence guiding Toulon towards the double.
9 Greig Laidlaw (Scotland)
The Scotland No 9 must be wondering what else he could have done to make it on to the plane to Australia. Laidlaw was in scintillating form during the RBS Six Nations, helping Scotland to third in the standings. He marshalled the pack brilliantly, while he was able to produce quick ball for the backs. Laidlaw, who can play at fly-half as well, was also near-faultless with the boot as he supplied a steady stream of points.
1 Ryan Grant (Scotland)
Another Scotland international who can count himself unlucky not to be heading to Australia. Grant was tipped by many to earn a call-up after some brilliant performances during the Six Nations but he misses out with Matt Stevens getting the nod instead. The Glasgow loosehead made his debut in the famous 9-6 victory over Australia last year and the 27-year-old hasn't looked back since.
2 Rory Best (Ireland)
The most notable omission from the British and Irish Lions squad announcement was that of Best. The Ireland and Ulster hooker was many people's favourite to start in the Test team, so for him not to even make the touring party came as a complete shock. Best, who has won 67 caps for Ireland and gone on to captain his country, is a strong ball-carrier and a defensive general.
3 Mike Ross (Ireland)
The Leinster tighthead is one of the top scrummagers in the game and he has been credited for helping stabilising Ireland's set-piece. A late bloomer on the international scene, the 33-year-old Ross has gone on to be the cornerstone of the Irish pack since 2011 and his form during the past year in particular had moved the former Harlequins man into contention for a Lions spot.
4 Joe Launchbury (England)
The tour to Australia has perhaps come a year too soon for the England lock. Launchbury burst on to the international stage in 2012 with a number of impressive displays during the autumn Tests - with the 22-year-old being named the QBE man-of-the-series. The Wasps forward carried this form into the Six Nations, with Launchbury catching the eye with his work-rate in the loose.
5 Jim Hamilton (Scotland)
The 30-year-old's hopes of ever appearing for the Lions now look to be over. Hamilton, who was overlooked for the 2009 tour to South Africa, did everything asked of him in the Six Nations - with some towering lineout work as well as being a defensive rock. The Gloucester lock started every one of Scotland's games as they went on to finish third - registering wins over Italy and Ireland.
6 Ryan Jones (Wales)
The former Wales captain can count himself very unlucky not to be involved with the Lions - although it is likely that injury ultimately ended his chances. Jones performed brilliantly during the Six Nations and looked rejuvenated when he stepped up to take over the captaincy in Sam Warburton's absence. To make matters worse for Jones, he has also been overlooked for Wales' summer tour - with Robin McBryde giving youth a chance.
7 Chris Robshaw (England)
The decision to leave Robshaw at home pushes Best's omission hard as the biggest shock from the Lions squad announcement. The England captain had been touted as a possible skipper for the tour, with Robshaw having led club and country with distinction. However, the loss to Wales in Cardiff and the return to fitness of Dan Lydiate appear to have counted against him.
8 Johnnie Beattie (Scotland)
Beattie must have fancied his chances of emulating his father and playing for the Lions after some sterling displays for Scotland. The Montpellier No 8 might have been surprised to have started the Six Nations, however he proved he was more than worth his place in the side. Beattie's ability to get over the gainline and defensive work, though, were not quite enough to earn him a place.