People regularly queue outside of SIGNAL IDUNA PARK. But on Thursday evening, for perhaps the first time ever, they did so because of a book. As part of the lit.Ruhr festival, Hans-Joachim Watzke gave a reading of his new biography ''Echte Liebe: Eine Leben mit dem BVB'' (True love: a life with BVB). Former Black & Yellow head coach Jürgen Klopp was the guest of honour. The 400 guests who attended the event enjoyed an evening filled with laughter.

Watzke, a Sauerland native with roots in the Ruhr, tends towards pessimism going into games. Speaking on stage, he selected a particularly apt extract from the book: "If such a thing as a happiness gene exists, well it's not particularly pronounced in me.'' Klopp burst into laughter: "That's true." After all, the current Liverpool coach is quite the opposite. The cheerful chap from the Black Forest defined an era at the club, winning the league title in 2011 and then a domestic double in 2012. But Klopp's time at the club wasn't just characterised by success out on the pitch; it was also marked out by the amiable sense of warmth exuded by the head coach. It comes as little surprise then that the former BVB coach comes up again and again in Watzke's biography, and it was highly fitting that Klopp was able to attend the reading. The FIFA World Coach of the Year was keen to stress how special the time they spent working together was, and also emphasised the importance of everything Watzke has done for the club. ''Relationships like this are something special in today's football,'' says Klopp: ''A classic male friendship.''

''Never before had I had a relationship like the one I had with Jürgen.''

''Never before had I had a relationship like the one I had with Jürgen during his seven-year spell at the club,'' writes Watzke: ''And I will probably never have a relationship like i again." What is it that connects Klopp and Watzke? Both are successful people. Both are almost romantically in love with football. Both bear the influence of their fathers. "I'm a daddy's boy," says Watzke with a smile: "My mother has complained that she's barely mentioned in the book." Klopp says: "To put it succinctly, we both have quite a big mouth. But we can take as good as we give too." Indeed, the two friends love to engage in a bit of banter on stage - A small side blow among friends on stage - the audience responds with resounding laughter.

Watzke became treasurer of Borussia in 2001 and then CEO in 2005. Few others can match his years of esteemed service for the club. He has received several requests for a book over the years, and, up till now, had turned them all down. "Nobody believes me when I say this, but I actually don't really like being in the spotlight.'' In the end, a melancholic reflection forced him to change his mind: "Maybe you'll have grandchildren some day, and maybe you'll want to show them that you didn't just spend your life clowning around.'' So it was that he resolved to tell his story, once and for all, and then never again.

"...unless the man in charge is Jürgen Klopp."

Michael Horeni, sports editor at the Frankfurter Allgemeine Zeitung, was awarded the contract as author. After many long conversations, he conceived a book in which his own insights are smoothly interspersed with the stories told by Watzke and Klopp. Topics covered include the club's escape from the threat of insolvency, the bomb attack on the team bus, the title-winning seasons as well as behind-the-scenes anecdotes.

Alexander Bommes, moderator for the evening, asked the following question to bring proceedings to a close: "Mr. Watzke, if Friedrich Merz became Chancellor of Germany, would you rather be made Finance Minister or Economics Minister? Watzke: "I'm no good playing second fiddle." Unless indeed the man in charge is Jürgen Klopp (in football at least).

The German language book is now available for purchase via the club's online shop!