mm,
this is an excellent question. It would all have to do with my upbringing. Statistically, I probably would have been a blacksmith or maybe a musician. But if there ever were a chance at all, thinking back to my life as a kid up to 12 years old, if my life was harsh at home and my parents thought I could have a better life elsewhere, I'd have joined the Church. I'd like to think I would have joined one of the Military Holy Orders, early on in the Crusades, part of the "Crusade and join an Order" bandwagon as I was very susceptible to that when I was younger, getting wrapped up in something "cool." (We all remember the Top Gun leather jackets) But then I would have found my calling there. It all would have had to do with whoever I met, and influenced me one way or another as to which order I would have joined.
Right now, thinking about it, Knights Templar, definitely. I was awkward as a kid, and shied away from women anyway, so the chastity and celibacy would have been actually easy at first. Also, because of a Fr. Robert I had as my Senior religion teacher in High School. Not only that, but it was his classroom where we had detention, which I am sheepishly proud to say I made the "dean's most wanted list" in my class yearbook. Fr. Robert was Benedictine, so right now, I'd lean heavily towards the Poor Fellows of Christ and the Temple of Solomon. I really have come to respect, admire, and appreciate every Benedictine I've met, even the nun who would throw the eraser at me, because after all it was my bad that she threw it.
On that note, a lot of the conspiracy stuff about the Knights Templar, I just can't believe in whole. They as a whole, were warrior monks, devoted to their cause and to their Christ, and especially to each other. That isn't something too far distant than believing they were the SEALs and SOCOM of their day, if anything, at least in spirit and tenacity. They were feared because they were powerful. But as another member said something similar and I was taught in school, "power doesn't corrupt, it's just easily sought by the corruptible as those that aren't have better things to strive for." I saw plenty of people wash out of USCG Basic Training because they were there for all the wrong reasons. I can't even imagine something like BUD/S or Fort Bragg. And that's who the Knights Templar were.
All of these accounts with "DaVinci Code," "Assassin's Creed," and "Kingdom of Heaven" (especially Kingdom of Heaven because the sources I've read said Guy and Reynold weren't even Templars to begin with) have just spread a bad light on a rather otherwise great order that fell apart because of only a few bad apples within the crop. But isn't that how it always goes? And then past that? My theory is that the Knight's Templar always have some level of mystique and clout, probably more back then than they do now, so like a Coastie going to a senior prom with a taller stack than he had actually earned (and yes, witnessed that FUBAR), they called themselves Templars. They jumped the bandwagon. I just have to believe that when the Knights Templar disbanded, probably 90% stayed within the Church in some form or fashion... at least that's what I hope.
Beyond that, there is no greater way to go out, than with yer boots on, protecting those behind and around you. I believe regardless of what era I was to be born in, that would have always stuck with me, as that is something that as far as I can tell, was never taught by my parents. They were all shocked (most of the family) at my choice to serve, especially after 9/11 and choosing the US Coast Guard for all the RIGHT reasons, not because they "didn't go to war" (which is a SNAFU in and of itself, ask any Marine worth his salt)
ok, off the soapbox
put it plainly, if I could ever devise a way, I'd serve a holy military order. Either that, or later on, with William Wallace, Robert the Bruce as a 10 pound man, or a gallogaleigh... funny too, my grandmother's maiden name on my mom's side: O'Niell. So maybe if there was a previous life, maybe that's why I am the way I am now
**edit**
Knights Templar were following the Cistercian Order, not the Benedictine, although they followed the Benedictine Rule. My mistake and modified.