Category: Insurance case law · Reviewed by Chrissie Anderson, Client Executive · Last reviewed June 2026
Court of Appeal decision holding that riots and civil disturbances over several days across many locations did not constitute a single “occurrence” for aggregation purposes — a leading authority on occurrence-based aggregation.
The case arose from the widespread civil disturbances that took place in Indonesia in May 1998, during which numerous Chinese-Indonesian-owned businesses across Jakarta and other Indonesian cities suffered looting, arson and other damage. The disturbances took place over several days and at many different locations.
Mr Mann (a representative claimant within the Lloyd’s market) was a reinsured under a programme issued by Lexington Insurance Company. The underlying direct insurance covered properties in Indonesia against risks including riots, strikes and civil commotion. The reinsurance contained aggregation wording tied to “any one occurrence” — a formulation common in property and reinsurance contexts.
Losses across the affected properties amounted to a substantial sum. The reinsured argued that the disturbances should be treated as a single occurrence, so that they aggregated within the per-occurrence limit and exhausted only one limit. Lexington argued that the events at different locations and on different days were separate occurrences, each subject to its own limit (with the obvious consequence for the reinsured’s net recovery after deductibles).
The Court of Appeal was asked to construe the “occurrence” wording in the context of geographically and temporally dispersed civil unrest, and to apply the principles of aggregation developed in cases such as Caudle v Sharp and the earlier US-influenced jurisprudence on “occurrence” in property and liability reinsurance.
The central issue was whether the events that took place in Indonesia in May 1998 — characterised broadly by a wave of civil disturbance affecting many properties across many places over several days — constituted “one occurrence” for the purposes of the aggregation wording. The court had to consider the meaning of “occurrence” in property reinsurance, how it relates to and differs from “event”, and what unifying factors (time, place, cause) would be required for multiple incidents to be properly compressed into a single occurrence.
The case also raised broader questions about how to characterise large-scale civil disturbance for insurance purposes, with implications for political violence, terrorism and riot cover more generally.
The Court of Appeal held that the disturbances did not constitute a single occurrence. The court applied the now-familiar test that an occurrence (closely related to “event”) requires a unity of time, place and cause sufficient to constitute a single happening for aggregation purposes. Where the disturbances were spread across many days, many cities and many separately-staged incidents, that unity was missing.
The court accepted that the disturbances shared a broad common context — a single period of widespread civil unrest in Indonesia — but held that this contextual unity was not enough. The aggregation language required something more specific: a single occurrence at which the underlying losses could be located. A pattern of disorder spread over days and locations was a series of occurrences, not one occurrence.
The court considered earlier authorities on aggregation, including English and US case law on civil disturbance and “occurrence” wording, and reached a result broadly consistent with the line of decisions including Caudle v Sharp. It emphasised the importance of construing the wording in its commercial context and not stretching “occurrence” to bear a meaning that the parties had not chosen to give it.
The practical effect was that limits applied at a more granular level than the reinsured had hoped, with a substantial reduction in net recovery once multiple deductibles and limits were applied.
(Detailed quotation is paraphrased here as exact wording has not been verified against the report.)
For the purposes of an “occurrence”-based aggregation clause, multiple incidents will be compressed into one occurrence only where there is sufficient unity of time, place and cause to constitute a single happening. A broad contextual unity — for example, a single period of civil unrest in a particular country — is not by itself sufficient. Geographically and temporally dispersed incidents will generally constitute separate occurrences even if they share a common political or social cause.
Mann v Lexington is a leading English authority on the meaning of “occurrence” in property and reinsurance aggregation wording, and remains regularly cited in disputes about riot, civil commotion, political violence and terrorism cover.
For brokers placing property, political violence and terrorism cover, the case has direct practical relevance. It establishes that “occurrence” wording will not necessarily aggregate dispersed incidents, with major consequences for limits, deductibles and reinstatements. Where systemic civil disturbance is foreseeable, careful drafting — sometimes using “hours clauses” or specific aggregation provisions tailored to the peril — is essential.
For reinsurance buyers and writers, Mann v Lexington sits alongside Caudle v Sharp and Lloyds TSB v Lloyds Bank Group Insurance as a pillar of the modern law on aggregation of dispersed losses. It confirms the structured approach: identify the aggregation language, identify the unifying factor, and test it for the required unity of time, place and cause.
The case is also significant for the broader law on political violence and terrorism cover, where the question of what constitutes a single occurrence is often acute. It is regularly invoked in disputes following coordinated terrorist attacks, mass civil disorder and similar large-scale events.
For policyholders, the case is a reminder to scrutinise occurrence wording carefully when assessing exposure to large-scale dispersed perils, and to consider supplementary aggregate cover where the wording is unlikely to compress losses into a single limit.
By Matt Bartlett, Director, on 2026-06-06. Next review: 2026-12-06.
This entry is part of the Apex Insurance Wiki. Last reviewed by Matt Bartlett on 2026-06-06. Apex Insurance Brokers Limited, FCA FRN 724952, Companies House 07014570. Not regulated advice — consult your broker on your specific position.
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