Some of them actually went on to see action in the tournament as the hosts crashed out at the pool stage.
Preliminary squads for pre-tournament training camps are always bloated to ensure there are numbers for live sessions, to account for injuries and other similar factors.
It also allows the coaching staff to get a closer look at players who they don't normally get chance to bring into camp.
Because of the bloated nature of the squads, it means some left-field names tend to get a call up and four years ago, there were certainly a few that were filed under 'unexpected'.
Here are some of the players you might forget were named in the squad...
1. Danny Cipriani
He's never far away from the headlines in regards to England and it was the same four years ago. Often forgotten, the mercurial fly-half did actually make the initial training squad but wasn't selected in the World Cup squad. He's probably in the exact same position four years on.
2. Lee Dickson
His last of 22 caps in the England jersey is when he played against the All Blacks during the 3-test series in summer 2014. However, he ended up being the fifth choice behind Ben Youngs, Danny Care, Richard Wigglesworth, and Joe Simpson.
3. Alex Corbisiero
The then 27-year-old, capped 20 times by England, made his last appearance in the white jersey against France in the build up to the 2015 Rugby World Cup. He won the Premiership and European Challenge Cup in 2014 but knee, shoulder and lower-back injuries had limited club and country progress. Following injuries, he's intitially left Saints in January 2016, planning to return to the game after a year break but changed his mind and persued a career in the media.
4. Calum Clark
The now 29-year-old flanker made his England debut when he started against France on 15 August 2015 in the build-up to the Rugby World Cup. This would be his only cap to date. He's now at Saracens but has little or no chance of making Eddie Jones' training squad.
5. Matt Kvesic
The then Gloucester back-rower had been part of the conversation for some time and had been in a number of squads. However, due to stiff competition, he'd struggled to get into matchday squads and has won just three caps to date. Now with Exeter Chiefs, the flanker is again close to being considered but probably be edged out of the final squad once again.
6. Ed Slater
He failed to win a cap as he faced stiff competition from Dave Attwood, Maro Itoje, George Kruis, Courtney Lawes, Joe Launchbury and Geoff Parling. After making his way into Eddie Jones' plans at the beginning of 2016 though, he was injured again and as yet has not made the extended squad since. Chances of going to the 2019 Rugby World Cup are very slim.
7. Stephen Myler
A one-cap wonder. It was bit of a shock when he made the squad with Danny Cipriani, George Ford and Owen Farrell filling the three other fly-half slots. Now playing in the Championship with London Irish, he's definitely not going to be involved in Eddie Jones' training squad this summer.
