This is the first book to offer a detailed and systematic analysis based on original research of the ideology, electoral and governmental performances, organisational model, type of leadership and member activism characterising the Lega Nord (Northern League) under its founder, Umberto Bossi (1991–2012). Created thirty years ago, the Northern League has now been shelved by a new leader, Matteo Salvini, who has replaced it with a brand new party that bears his own name: the Lega per Salvini Premier (League for Salvini Premier). However, as western Europe continues to witness the sustained growth of populism within its borders, “Bossi’s League” offers a case study of a populist party moving very early on from protest to government. The book identifies the Northern League’s consistent and coherent ideology, its strong leadership and its ability to create communities of loyal partisan activists as key ingredients of its success. It is shown that the League has much to teach us about how populists can achieve durability and rootedness and how parties of all kinds can still benefit from a committed and dedicated membership today.