General partner (Komplementär)
Also: Komplementär, Komplementärin, persönlich haftender Gesellschafter, Vollhafter, personally liable partner
In short
The general partner is the partner in a KG who is personally liable without limit, and manages its business. A GmbH or UG can also be the general partner, as in the GmbH & Co. KG.
General partner (Komplementär) explained
Every KG needs at least one general partner (Sec. 161 (1) HGB). They are liable for the partnership's obligations personally and jointly and severally, like an OHG partner, and an agreement to the contrary has no effect on third parties (Sec. 126, 161 (2) HGB). In return, they manage the business and represent the KG externally, because the limited partners are excluded from this. If the general partner is a GmbH, it is liable without limit, but only with its own assets, and usually receives a liability fee for this. If no natural person is personally liable, the company name must indicate this, for example with "GmbH & Co. KG" (Sec. 19 (2) HGB).