Their being so many popes throughout history I would assume some popes probably had inappropriate relationships that were covered up
Oh you betcha. there are multiple accounts of julius II having an affair and an illegitimate child with a women by name of lucrezia normanini in 1483. in addition to this he was rumored to have a string of lovers both male and female. and thats just one example of popes doing the nasty, there were several others. In fact the reputation of Julius's sexualized behavior was so infamous that during the reformation the protestants often cited his behavior as evidence of the corruption and sinfulness of the Papacy.
Several! Five of them were even married. Many had illegitimate children before assuming the pontificate.
Probably the most famous to have had sexual relations after assuming the pontificate would be Pope Alexander (of the Borja/Borgia family), who fathered at least four (that we know of) illegitimate children--one of whom was, of course, Lucrezia Borgia, with whom he was rumored to have an incestuous relationship with.
Benedict IX was ALL KINDS of messed up. He became pope at age 20, and ended up serving three separate terms as Pope before finally being excommunicated entirely, and is largely regarded as a massive embarrassment to the papacy. Word on the street is that he was very much into hosting orgies, sodomy, rape, bestiality and also murder.
Julius III was also the subject of a major scandal, and was accused of having sexual relations with his adopted teenage nephew, who reportedly slept in the same bed as him.
There were certainly rumors that Pope Paul II was gay--including one one that he died of a heart attack during sex with a man, though nothing definitively proven.
There are lots of rumors, in general, of popes having had inappropriate relationships, and LOTS of them involving the popes being gay--some of them are probably true, but it's also very likely that a good amount of them were created by those who opposed them.
Hello there!
Apart from the inappropriate relationships that other answers have covered, I'd just like to drop my two cents and mention that before 1074, although it was frowned upon, it was not explicitly forbidden for catholic priests to marry and have children; and this extended to Popes as well.
From a previous answer of mine:
After the proclamation of Anselmo da Baggio as Pope Alexander II in 1061, the Papacy was safely back in the hands of whichever Italian family managed to wrest its control. There was a real need to play up the spiritual supremacy of the church, not in the least exacerbated by the ongoing tensions that would lead to the investiture controversy. Indeed, Agnes, the widow of Henry III, Holy Roman Emperor, had tried to instate an imperial-leaning pope, but to no avail. So why celibacy? Surely, of all the things Alexander II could have done to strengthen the Papacy, "No Sex" couldn't have been high on the list? Well, he had come from one of the most prominent families in Milan at the time, the House of Baggio. The Milanese had always had a rather "strict" take on catholicism, even today, the clergy in the Lombardy region of Italy, where Milan is the capital, do not follow the same "Procedures" in mass as the majority of Catholics (mass in Lombardy follows the unique "Ambrosian Rite", rather than the standard "Roman Rite", except in those cities that were historically Milan's antagonists, notably Monza. Oh, how I could go on...). It is not surprising then, that in Milan at the time there was a strong current in favor of clerical celibacy, called "Pataria", which Anselmo had introduced with great success in Lucca, an Italian city where he had been bishop prior to his elevation to the papacy. (I cannot find an english source for this. The contemporary chronicler most cited is Landolfo Iunior. A good Italian source is L'Età della Pataria by Alfredo Lucioni, La Scuola, Brescia, 1990). Alexander II died before he could take any significant action regarding Clerical Celibacy, but his successor, Gregory VII (a Tuscan) entered office and came upon his writings. It was Gregory VII who in 1074 proclaimed that all clergymen who had taken a wife and/or fathered children were stripped of their authority. So, to answer your question, we can say that in 1074, it became unacceptable for clergymen to have children of any kind, whereas before, it was frowned upon, but not necessarily prohibited.
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