Mike Ford and John Wells have joined England's new-look coaching set-up on one-year rolling deals, but talks over Brian Ashton's involvement are ongoing.
Ford and Wells will coach England ahead of Sunday's Barbarians game
Ford, a former Great Britain rugby league international, has departed Saracens to become defence coach.
Former Leicester coach Wells has left his position at the National Academy to take over as forwards coach.
The RFU still hopes to appoint Ashton as attack coach before England leave for their tour of Australia on 29 May.
Ford and Wells will take on their coaching duties with immediate effect, and will help England prepare for their game against the Barbarians on Sunday.
"I'm delighted John and Mike will be joining me in a new coaching team which will take us forward," said England head coach Andy Robinson.
"This is an exciting time for England leading up to the Rugby World Cup and I'm confident the coaching set-up we're assembling is capable of helping us successfully defend our title."
There's nothing like coaching your own country
New England defence coach Mike Ford
Ford comes from a rugby league background - as did his predecessor Phil Larder - and started his coaching career with Oldham after winning 10 Lions caps as a player.
He switched codes to become Ireland's defence coach at the start of 2002 and moved to Saracens in a similar role in 2004.
The 40-year-old initially combined the two roles but took on a full-time role as head coach at Saracens, as well as going on the 2005 Lions tour.
Ford told BBC Sport he had turned down a more lucrative offer to join Wales as their defence coach.
"My aim is to turn England into the best defensive team in the world," Ford told BBC Sport.
"I'm very proud. I coached Ireland and loved it, but there's nothing like coaching your own country," he said.
Ford also said his departure from Saracens was partly down to his unhappiness with the club's plans to return him to his defensive role after he spent last season as head coach.
Wells made 367 appearances for Leicester during a 16-year playing career before becoming forwards coach in 1998.
He was appointed head coach in 2004, and then joined the National Academy in 2005.
"I see this is a natural progression both for England and myself as a coach," said Wells.
In a further appointment, former Bath and England full-back Jon Callard will coach the second-string England Saxons side in their Churchill Cup campaign.
The appointments follow the RFU's decision to revamp their coaching structure in the wake of two disappointing Six Nations campaigns.
England, who defend their world title next year, have finished fourth in the Six Nations for two seasons in a row and slipped to sixth in the IRB world rankings.
After an extensive review of England's performances, the RFU sacked defence coach Larder, attack coach Joe Lydon and kicking coach Dave Alred.
An Elite Rugby Director, overseeing all aspects of representative rugby in England, is also still to be appointed.