Eddie Jones is braced for his toughest Six Nations yet but the England head coach is wary of declaring the gap with the southern hemisphere has narrowed.
Twickenham was the stage for victories over Argentina, Australia and Samoa that elevated Jones' record to 22 wins from 23 Tests at the halfway stage of his four-year reign.
England have delivered successive Six Nations titles on the Australian's watch but with Ireland routing South Africa and Scotland thumping Australia, he understands the trials ahead.
"The British and Irish Lions series against New Zealand showed what the standard will be," Jones said.
"The quality of the players that went on the Lions series showed that the quality of the domestic teams in Europe at the moment is high, therefore the quality of the players is high.
"I would anticipate that this Six Nations is going to be harder than any of the Six Nations we've played in previously.
"But I wouldn't get too excited that the north-south hemisphere gap has gone. You're playing against teams that have played 14 Tests - the All Blacks have played 14 Tests already this year.
"You've got to look at where they are, but definitely the European sides are moving in a positive direction."
Jones opted against naming his player of the series - a custom he has adopted to date - but Elliot Daly was name checked after running in two eye-catching tries in Saturday's 48-14 victory over Samoa including one outstanding solo effort.
The Wasps midfielder has been converted to a predatory wing by Jones, who has been rewarded with a return of six tries from 16 outings after telling him to "play as a centre and defend on the wing".
"Elliot's had a really good series. He's probably, of all the Lions guys, come back the best, got more spring in his step," Jones said.
"I always thought he was a natural winger when I watched him play. Left foot. Speed. Ability to come in off his wing. Exactly all the things I thought he could do he can do at Test level.
"You never think about the limit for the player. You always think they can get better.
"There's no reason why he can't get better now. He can be a better player next year than he is this year.
"He can get quicker, he can get stronger, he can get better conditioned than he is, and he will. First he's got to get in our side, then he can get into a world XV."
Manu Tuilagi remains on England's radar with the powerful centre scheduled to make his comeback from the latest episode of his injury-blighted career - knee ligament damage - in December.
"All I can remember is Manu playing at his best against New Zealand. If he is capable of doing that consistently then there's a chance of being in our squad," Jones said.
"We're going to find out his desire to work hard. As you get older it gets harder to come back from those injuries so we'll see. Time will be the teacher."
England's Piers Francis charges forward against Samoa.