My mom is extremely insecure, emotionally immature, and has more or less completely severed ties with both sides of the family for one reason or another. She takes things personally and out of context, so over time everyone feels like they're walking on egg shells around her so she doesn't have a fit or leave the room crying.
Over the last few years my dad has started keeping silent about any of it and has also distanced himself from family, so they come to me asking what's up when I truly have no idea. Every so often I'll get a text from my mom, usually something along the lines of "you better not tell <aunt/uncle/cousins/grandma> about <really dumb small thing that's none of her business>!"
A few months ago I finally let her have it and said I'm not getting in the middle of this anymore. I'm not lying for anybody, or stunting my relationships just because she's ruined all hers. She said "I feel betrayed by my own family". Sorry, but you did all that on your own, and now that people are actually trying to reconsile for WHATEVER they did, stories are coming out about when we were kids when I alway second guessed if she was going a little hard on the spankings, if some punishment was warranted at all, lots of other shit...
The biggest one is she has this obsession with gifts being used as a "control tactic". She thinks my grandma only gives anybody gifts as a way to guilt them into coming to visit her. My aunt, who has been nothing but kind throughout this whole thing, said when I was the only grandchild, nothing was ever good enough for my mom. She would always make up an excuse to exhange whatever gifts family would buy me for something else...now, we were tight on money growing up, so a small part of me understands this next part, but it's also pretty shitty. Allegedly they started keeping track and suspected she was returning my gifts, would buy something of lesser value, and keep the rest of the cash for herself.
That's only the tip of the iceberg. I love her, but it's really hard to be empathetic and understanding with her when you can't be honest without her losing her shit. She threatened suicide when I told her I wasn't getting involved in this current round of shit. Her mom was a schizophrenic who killed herself when my mom was young, so her family history is a bit fucked up too.
TL;DR: My mom is generally the catalyst for any family drama ever.