There are many words that in English are conjugated in the past tense to end in "-n": grow goes to grown, sew goes to sewn, throw goes to thrown, etc.. I'm guessing it was probably the regular ending in English in some long past time. But as every growing child knows, the more common form has become conjugating the past tense to end in "-ed": jog goes to jogged, flog goes to flogged, clog goes to clogged, and so on. Even completely foreign words are usually regularized in English to have their past tense end in "-ed"; abet goes to abetted, blink goes to blinked.
I was wondering two things: Did all the words that are conjugated to end in "-n" in the past tense come from a shared language family, or was it a "regularization" procedure as well back when it was more common? Did something precipitate the change from "-n" to "-ed", like a conquest, or some other notable historical event?