Last Updated: 13/05/13 4:10pm
Australia captain Horwill has become the backbone for both club and country.
The 27-year-old was named Wallabies skipper in the build up to the 2011 Rugby World Cup - with Horwill lifting the Bledisloe Cup in the run-up to tournament and then a third-placed finish in New Zealand.
Horwill has appeared 35 times for Australia, with only a run of unfortunate injuries (knee, foot, hamstring) denying him more caps.
The Brisbane-born lock came through the age-grade system in Queensland before making his Super Rugby debut against the Waratahs in 2006.
Horwill would play 39 successive games for the franchise, taking over the captaincy in 2007 and leading the Reds to the title in 2011 and the Australian Conference crown the following season.