What is the oldest type of reinsurance?

The Oldest Form of Reinsurance: Facultative Reinsurance

Long before modern insurance models took shape, a foundational practice emerged in the 14th century that laid the groundwork for risk management in the industry: facultative reinsurance. As the oldest form of reinsurance, it began as a practical solution for insurers facing unusually large or unpredictable risks they weren’t equipped to handle alone.

Facultative reinsurance operates on a case-by-case basis. Unlike automatic or treaty arrangements, each policy is individually underwritten and negotiated between the insurer and the reinsurer. This gives both parties full discretion—hence the term "facultative," meaning optional. If a risk is deemed too high, the reinsurer can decline it. This selective nature made it the go-to method when reinsurance was still in its infancy.

What’s more, facultative reinsurance can be structured on either a proportional or non-proportional basis. In the proportional model, both the premiums and losses are shared according to a pre-agreed percentage. In non-proportional setups—like excess of loss treaties—the reinsurer only pays out if claims exceed a certain threshold.

While treaty reinsurance has become more common in today’s fast-moving markets, facultative reinsurance remains relevant for high-value or unusual risks—think natural disasters, large industrial projects, or unique life insurance cases. Its longevity speaks volumes about its flexibility and enduring utility.

From medieval trade routes to modern skyscrapers, the principles behind facultative reinsurance have stood the test of time. It wasn’t just the first solution of its kind—it helped shape the very idea of risk sharing in insurance as we know it.