Cobblers have signed Lewin Nyatanga on a season-long loan from Barnsley.
The 27-year-old helped his parent club to promotion from Sky Bet League One last season.
He made 28 appearances during the campaign, all of which came before the turn of the year.
And the Wales defender, who has won 34 caps for his country, has experience of the Premier League, having featured in the top division for Derby County.
“Lewin is another fantastic addition for the club,” said Cobblers boss Rob Page.
“He has got a wealth of experience at this level and higher and we are delighted to get him.
“We wanted to strengthen in central defence and Lewin is a good left-footer who can also play at full-back.
“He gives us options and with the loan rules this year we know how important it is to have players who can play in a number of positions.
“Lewin is a great professional, he’s a good age and I feel we’ve improved the group again.”