I was playing as England and had brushed up against the "back off or get discommunicated" a few times with Scotland. I had, at best, iffy faction with the Pope and then just a few turns after I finished off the Scotts by taking Inverness, I got the Templar guild. I'd converted Inverness to a town and got the guild offered 2 turns later.

I had built a total of 2 cav units. One mail knight and one hobliar at about turn 2 to help with the initial land grabs and those were built at Nottingham.

I've played the England campaign alot and that's the first time I've gotten a Knight Guild of any sort offered. I have zero clue how or why I got them this time.