Attacked and strangled by Tunna and Gommon, henchmen of Ludmila’s daughter-in-law Drahomira.
Feast Day September 16
From Wikipedia:
She is venerated as a patroness of Bohemia. She is considered to be a patron saint of Bohemia, converts, duchesses , those with problems with in-laws, and widows.

see wikipedia: https://en.wikipedia.org/wiki/Ludmila_of_Bohemia

First historically documented Duke of Bohemia. He reigned from about 867.
Borivoj and Ludmila were converted to Christianity through the efforts of Saint Methodius.

Wikipedia: https://en.wikipedia.org/wiki/Bo%C5%99ivoj_I,_Duke_of_Bohemia