mediatize

To make (a state or leader under the Holy Roman Empire) into a mediate vassal rather than an immediate one, directly under the emperor; (by extension) to annex while preserving certain rights and titles.

In all, 112 imperial Estates were mediatized or lost to France, including virtually the entire church lands east of the Rhine […].

To reduce the effect of (something) by introducing a mediating agent.

To filter (an event etc.) through the mass media; to exploit (something or someone) for media exposure; to propagandize via social media.