Ineos, smarting from their Tour de France blowout, have re-signed Australian Richie Porte who finished third in the race this year as they rebuild the team in the post-Chris Froome era.
Porte, 35, rode for Ineos's previous incarnation Team Sky from 2012-15, winning the Paris-Nice race twice.
Ineos team principal Dave Brailsford said Porte -- who will leave Team Trek to return to Ineos -- is just the type of rider who helps build a team.
Ineos are losing Britain's four-time Tour de France champion Froome at the end of the season but have invested in young British talent with Adam Yates joining.
Another highly-rated Briton, Tom Pidcock, has also been added as Ineos hope to regain their dominance of the Tour de France as they mould a new unit around 2019 winner Egan Bernal.
Dani Martinez, a 24-year-old Colombian, who won Tour warm-up event the Criterium du Dauphine, joins from Education First and 25-year-old Belgian Laurens De Plus arrives from Jumbo-Visma.
Prior to this year's race Ineos had won the Tour seven times in the past eight -- six of them thanks to a British rider.
But this year Bernal failed to finish and the team could not place a rider in the top 12, won just one stage and were powerless to prevent Jumbo controlling the peloton.
"This season we have seen a change in both individual performance levels and the collective strength of teams," said Brailsford.
"Riders are better prepared and teams more organised. The intensity of competition is increasing and it's getting more difficult to win."
Brailsford said Porte had the advantage of already knowing the team.
"Richie's richly-deserved podium at the Tour de France once again demonstrated that he's one of the best riders in the peloton," he said.
"We already know how each other works, he knows how we race, and with the wealth of experience that Richie now has he has so much to offer the team."
Piddock, a former cyclo-cross rider, won the under-23 "Baby Giro" in September.
"It's clear Tom is one of the most exciting young riders in world cycling and part of a new era of incredible all-round talents. We’re witnessing a new trend in cycling, with an emergence of young riders who come from a broader, multi-disciplined background."
Froome is due to round off his Grand Tour story with Ineos in this year's Vuelta a Espana which runs from October 20 to November 8 before he joins the Israel Start-Up Nation team.