The sustained noise that rose up through 75,000 ribcages. The veteran battering rams leading the line for each side. The red, blue and shared black. And the historic concrete suit and steel lapels of the San Siro. It was hard to escape the weight of history on a fixture with more than a century behind it.

As both sets of fans bounced, clapped and sung for very different reasons at fulltime, it was impossible to imagine anyone wanting this fixture to be played anywhere else. But they do. Both these clubs are looking to move away from the tradition that binds them and find a home that they, not the local council, own. If a solution that brings the clubs more revenue cannot be found with the local government, both appear prepared to look elsewhere, even way out in the suburbs. Such a move would likely see an abandoned San Siro demolished.

"We love this place, it is ours," Inter fan Lorenzo told DW, as those in blue and black sang, drank and set fireworks off into the night sky. "It was a perfect atmosphere in the stadium and we're going to Istanbul [for the final], not them."

A rivalry of cousins

The rivalry between the two is distinct, according to Alessandro Jacobone, a freelance journalist and vice president of 'milanisti1899' fan association.

"It is quite common to have an opposing fan among friends, relatives, or co-workers, here in Milan referred to as a 'cousin'," he told DW.

"It is also common to spend days eagerly awaiting the weekend, engaging in banter and lighthearted discussions. This has always been the case, and the Milan derby can be considered unique precisely because of this."

Sharing the way the two Milan clubs do is anathema to modern top-level European football. Fans are squeezed, players are hoarded in bloated squads, stadium revenues are maximised. And with that often comes a new badge, an uneven TV rights deal and a new out-of-town mega arena.

"At the moment, fans are not thinking about it," Lapo de Carlo, president of Inter Milan fan radio station Radio Nerazzurra, told DW.

"There has been talk of a new stadium for more than twenty years. Italian politics is guilty of a lack of interest in the matter of owned stadiums, it has obstructed a law that would allow Italian clubs the possibility of owning stadiums and for years Italian football has been hostage to this situation."

Inter underdogs in the final

While fans may not be thinking about a stadium move just yet, those of an Inter persuasion are thinking about the final on June 10.

"Against City, of the sheiks, or Real, which is the most powerful team in Europe, it's tough for Inter," continued de Carlo. "[Simone] Inzaghi's team will be up to it but it's likely that it won't be enough."

That a club the size of Inter will be a huge underdog against either of the other two semifinalists makes it easier to understand the desire for change. Twenty years ago, a Milan derby in a Champions League semifinal featured a number of the world's best players: Javier Zanetti, Hernan Crespo and Fabio Cannavaro for Inter, Clarence Seedorf, Paolo Maldini and Andriy Shevchenko for Milan.

Both have tried foreign investment models since, with Inter still under Chinese ownership. But the current crop on show for the sides third and fifth in Serie A looked a notch below their predecessors on Tuesday, even if Inter deservedly made a first final since they beat Bayern in 2010.

Change required to compete?

In isolation, football retains the ability to deliver the sort of unexpected results that led these two to this point, and it may well do it again in Istanbul for the final next month. But until this season, Inter hadn't gone past the Round of 16 since that 2010 win, while Milan had reached the last eight just once since the last of their seven titles in 2007.

Increasingly, the only realistic way to compete with the superpowers old and new, seems to be to match their money. The Milan clubs feel they must concern themselves with oil states, rather than the city council, if they are to hit these heights again.

"The fact that both teams are striving for growth to reclaim their place at the top of Europe makes this rivalry even more intense," explained Jacobone. But, for him, the venue is not as important as it may seem to outsiders.

"The derby will never lose its allure and intensity, even if the teams were to play in separate stadiums in the future. On the contrary, having their own stadiums will further fuel the rivalry and the desire to establish themselves as the city's true owners."

As Alessandro Bastoni had a kickabout with a rabble of players' children in front of the Milan fans in the Curva Sud and his teammates danced in front of their own supporters at the other end, there was little doubt who owned the city on Tuesday night. But it is the question of ownership of their home and, perhaps, the clubs themselves that may define whether the next 20 years will see another Derby della Madonnina on the grandest stage or, indeed, in the San Siro.

This article was edited by Jonathan Harding