Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
I'm not sure what the て-form does in this sentence.
Could it be short for ている?
It's hard to say something definitive without more context, but it's probably either one of the followings:
No, it can't be short for ている. ヴァレンシュタインさんのことも含めて means "including things about Wallenstein"
Required, but never shown