It was said of the British Empire that the sun never set on it – of course, one day it did, and gradually the imperial pink washed away from vast swathes of the world. On Planet Football, empires also come and go, but currently the nation dominating Europe seems unlikely to budge any time soon.

Out of the eight teams in the semi-finals of the Champions League and Europa League, five are Spanish. Barcelona will appear in the last four for the fifth successive year, equalling the record of the Real Madrid of Alfredo di Stefano et al, whilst Jose Mourinho’s modern successors to that legendary side are re-establishing their proud pedigree as Europe’s most illustrious club following years of relative mediocrity (six successive Round of 16 exits may be fit for the likes of Lyon or APOEL Nicosia, but not for the nine-times continental conquerors). Both Spanish giants are on the verge of history – Real Madrid are seeking to be the first club to count European Cups in double figures, Barcelona meanwhile are aiming to clock up the first successive wins since Arrigo Sacchi’s fabled AC Milan side of 1990.

Real Madrid and Barcelona between them have taken six of the last 14 European Cups, whilst Valencia also featured in two finals at the turn of the millennium and Villarreal and Sevilla have also had strong campaigns. Los Che can console themselves with the UEFA Cup they won in 2004, which with Sevilla (2006, 2007) and Atletico Madrid (2010) makes it four wins in the last 10 finals in the second tier competition – this year is the second time in six campaigns that three Spanish sides have made the semi-finals, and with an impressive Athletic Bilbao side favourites to beat Sporting Lisbon, another all-Spanish final seems likely.

This renaissance in Spanish club football, shaking off the mid-Noughties pre-eminence of the English Premier League, which followed the dominance of Serie A through much of the late 1980s and 1990s, has coincided with the ascent of the national side to the summit of international football. From serial bottlers and combustible laughing stocks, La Furia Roja now appear near unassailable as England, France and Italy all attempt to overhaul ageing sides and recover from patchy recent tournaments.

Explaining the rise of Spain is natural enough – the overhaul of a youth coaching system, allied to a defined playing style, an end to corrosive inter-squad divisions (especially between Real Madrid and Barcelona factions) and an unusually talented group of players paid off after decades of investment – but looking at the reasons why La Liga rides so high is less simple.

A crucial difference is that English football (or Italian for that matter) secures its television contracts through collective bargaining, whereas in Spain individual clubs negotiate for the rights to show their own games – and here is where the top two press home their advantage, with Barcelona and Real Madrid earning head and shoulders above their league rivals. The imbalance is so great that in fact the elite out-earn all their adversaries across Europe in this respect, entrenching the financial advantage gained from larger stadia and the most aggressive marketing departments.

However, the depth of superiority runs too deep for this to be the chief cause. It is popular to point out that there is a large gulf between second and third in Spain, where Valencia and company repeatedly fail to bridge the financial gap, but this is hardly that difference from the recent domination of the Premier League’s big four and the current Manchester hegemony. To say La Liga is lightweight below the top two seems ludicrous, especially in the light of Athletic Bilbao’s accomplished demolition of Manchester United in the Europa League. Comparing the poor showings of the powerhouses of England and Italy to Spain’s regular success in Europe’s second competition is less a sign of pressured Premier League and Serie A clubs not caring for a tainted trophy, more of a drift in continental power.

A key factor alongside finance is the cultural advantage when it comes to signing South Americans and retaining talent. Despite the Premier League’s increasing multiculturalism, the shared language and style of football between Spain and Latin America means most European imports from football’s other great continent come via the Mediterranean. With the Calciopoli scandal helping to cause a decline in Serie A, Spain is left unchallenged as the prime destination. In addition, though Juan Mata and David Silva are among stellar Spaniards recently lured to England, it is more common for Iberians abroad to hanker after glorious returns in the style of Cesc Fabregas, Gerard Pique or Cristiano Ronaldo.

These last few years may have been defined by the rise and rise of Spain, but it is not necessarily the procession often presented. Barcelona have been excellent at times this season, with Lionel Messi in particular breaking records every other week, but they have at times seemed vulnerable too – Milan contained the Catalans manfully over two legs, with two penalties eventually their undoing, while Real Madrid have overhauled them in La Liga. Barcelona’s defence has also looked weaker than in recent years, while Josep Guardiola has hinted at a possible departure that, though the tiki-taka culture of Johan Cruyff will endure, could rock the Camp Nou. Real Madrid meanwhile certainly look fragile, as their tempestuous manager Mourinho is constantly the subject of speculation surrounding a confirmed desire to return to the Premier League.

Aside from possible ructions in the two dynastic forces, are there signs of a fightback? As in international football it seems to be coming from a revived and youthful Germany. Just as the Nationalmannschaft has come on leaps and bounds since staging the 2006 World Cup, reaching the Euro 2008 final, earning a second successive third place at the 2010 World Cup and representing a strong second favourites for this summer’s European Championship in Poland and the Ukraine, a bullish Bundesliga – having whipped a fourth Champions League slot from the sadly sliding Serie A – offers the strongest challenge to a Clasico final this season.

With Chelsea still too frail to realistically beat Barcelona over two legs, stopping another Spanish triumph is likely to fall to Bayern Munich. The Bavarian behemoth are desperate to make it to the final as it is played in their home stadium, and in Arjen Robben and Franck Ribery, clearly have quality to trouble any side, but it still seems likely that they will ultimately fall short against an imperious Real Madrid.

Should Bayern Munich fail to oust Mourinho’s side, German interest will still be present at the Allianz Arena in May – Real Madrid’s first-choice XI features the Teutonic talents of Mesut Ozil and Sami Khedira (with Turkish-born but German-Bred Nuri Sahin and Hamit Altintop in the squad too) – and next year could see a greater threat still, with Borussia Dortmund’s fast-improving youthful side likely to learn from this season’s tussles with Europe’s top sides.

Should Germany falter, Manchester City will surely get an easier group than last time and add to an already ominous squad, while their city rivals would also hope to improve on this season’s miserable European showings. The long-overdue return of Juventus will add spice and strength to the Italian efforts, while more wildcard challenges could come from the mega-rich Paris Saint-Germain or even Anzhi Makhachkala.

The threats posed by PSG and Anzhi shows the challengers can come from far and wide, comprising barbarians at the gates at the old citadels of European football as well as rival dynasties from the old elites. With possible managerial changes in the offing, theses strong pretenders could be coming at the wrong time from a Spanish perspective. Such external threats and internal stresses come with the territory of empire – this time next year it may be clear whether Spain’s domination sees another dawn or draws to a close.