Gatland led Wales to a brace of Grand Slam crowns in 2008 and 2012, while last season’s tournament triumph saw them become just the third team to win back-to-back Championships since the Five Nations became Six in 2000.
But claiming a hat-trick of titles and making history in the process would top the lot according to Priestland as every other country will have their hearts and heads set on stopping Wales from tasting glory yet again.
“This will probably be the most difficult of the lot to win,” said Priestland, who starts at fly-half against Italy when the Championship kicks off in Cardiff on Saturday afternoon.
“No team has won the Six Nations three times in a row and it’s a massive thing for us… we are looking forward to defending our title this year.
“It’s a massive challenge for us and we have to make sure we are up for it because every other team will be up for playing us. One of their main objectives will be stopping us winning the title again.
“We’ve never shied away from a challenge before, though, and we’ll take it head on.”
Priestland has won the battle for the keys to the No10 shirt in the tournament opener despite having missed out to Ospreys’ outside half Dan Biggar in Wales’ last outing against Australia at the start of December.
Gatland admits it was a tough call to pick between two inform playmakers and Priestland himself says he would have had no complaints had the selection call gone the other way.
The 26-year-old struggled with a long-term Achilles injury for much of last season and even the early parts of this one but he is now nearing his best once more and is determined to make the most of his opportunity when he runs out at the Millennium Stadium at the weekend.
“To be honest I didn’t think about the Welsh 10 shirt before coming into this camp. Playing over Christmas was about playing well for the Scarlets and enjoying my rugby. You have to have faith in the coaches and I am grateful they have picked me this time – I’m delighted to be playing,” added Priestland.
“A ruptured Achilles didn’t help my game but the break did help me both mentally and physically. As you get deeper into the season you feel your body a bit more but hopefully I will be able to keep going this year.
“This is probably the best season I have had since being a professional rugby player. There have been one or two blips but you can’t go the entire season playing at the very top of your game. The main thing is that I’m enjoying my rugby, and every game I play I just try to show that. It seems to be going okay for the moment.”