The 26-year-old French centre-half became Celtic's first summer addition when he completed a move from Toulouse.

"He's been a target for the club now for a quite a while," Lennon told Celtic's website.

"He has great attributes and has played at a very high level now for the last couple of years."

Jullien said on Friday he was sold on the £7m transfer after talking to compatriot Odsonne Edouard, the striker and former Toulouse team-mate who made his switch from Paris St-Germain two years ago.

"The fact that his wife's British will help him come and settle into a different culture very quickly," Lennon suggested.

"But, as a player, he has all the attributes we're looking for. He's one of those players whose career has progressed forwards all the time."

Jullien's signing was quickly followed by the arrival of 18-year-old midfielder Luca Connell from Lennon's former club, Bolton Wanderers.

"He's a very talented young player," the Celtic manager said. "He broke into the senior side with Bolton in the Championship.

"We've had a good look at him, have had good reports and he was away with the Irish senior squad training. The reports came back positive and we liked the look of him."

Both new signings watched from the sidelines on Saturday as Celtic won 2-1 in a pre-season friendly against Wiener Neustadt, who have just been relegated from the Austrian Second League.

The Scottish champions play the third and final game of their 10-day training camp on Tuesday against Swiss Super League side St Gallen.

"It's another step up in quality - that's what we're looking for now," Lennon added. "It's only two-and-a-half weeks until Sarajevo in the Champions League qualifiers.

"That'll be a good test for us and we'll get more game time into the senior players then."