While reading Wikipedia’s account of the life and work of Max Planck, a German physicist and founder of quantum theory, I came across this curious piece of information:
In March 1887 Planck married Marie Merck (1861-1909), sister of a school fellow, and moved with her into a sublet apartment in Kiel. They had four children: Karl (1888-1916), the twins Emma (1889-1919) and Grete (1889-1917), and Erwin (1893-1945)…
…During the First World War Planck’s second son Erwin was taken prisoner by the French in 1914, while his oldest son Karl was killed in action at Verdun. Grete died in 1917 while giving birth to her first child. Her sister died the same way two years later, after having married Grete’s widower. Both granddaughters survived and were named after their mothers. Planck endured these losses stoically.
The same husband; the identical sisters; their identical deaths; their identical daughters. Planck must have hated his son-in-law. The man was nothing but bad luck to the Plancks.

“I’m my own grandpaw!”
Seriously, I can’t figure out what’s what here. Who is “Grete”? Planck’s daughter?
In the past women often married their dead sister’s widower, you know, to keep it in the family. Etc.
I don’t remember what cultures have done this, and for how long, and when it started, but I remember learning that somewhere along the way.
Well — one must expect Plancks to be constant.
Yeah, marrying your sibling’s widow/widower wasn’t terribly unusual, but it does take it to another level that Grete and Emma were twins, and that they married the same man, and then died in the same way. That’s pretty interesting and cool (in a morbid sort of way, I guess).
@3 Thank you for that.
I do believe I’d rather spill my seed on the ground.
I found a picture of the widower. It might explain the birthing deaths.
I think they were twins, not identical twins.
Wait let me draw this out, okay, yeah I got it. Ha, that’s a good one.
Yeah, it used to be common back in the day for the sister of the dead wife to marry the widower. It was so that the children had a step-mother that wouldn’t neglect and abuse them. Happened a lot in the prairie states, I think.