So, Francis the first of France, had a major rivalry with Charles Vth of Austria and Spain. This rivalry notably started when Francis and Charles wanted both to be emperor of the Holy Roman Empire, but, being French and thus not at all part of the Empire, how could he be abble to run for this position? And what where the conditions to be elected Holy Roman emperor?
Sorry for the bad English, I'm not 100% confident on the translation of specific terms
Any ruler with enough money could run to be Holy Roman emperor, the title wasn't seen as a german title but a catholic and european one. During the Interregnum in the middle of the 13th century the brother of the king of England and the King of Castille were elected as kings of Germany, the title Holy Roman emperors held before beeing crowned by the Pope and nobody had a big problem with them not beeing German. As long as you had enough money th bribe the electors, you could become Holy Roman Emperor.