evidence: The Omicron subvariant BA.2.86 is derived from the BA.2 subvariant but has over 30 mutations in spike relative to both BA.2 and recently circulating subvariants such as XBB.1.5 (Fig. 1A), making its emergence a major concern since many of the mutations are predicted to confer escape from neutralizing antibodies1. [...] The Omicron BA.2.86 subvariant started to be identified by global genomic surveillance samples collected from 24 July 2023 onwards, but because of the reduced rate of surveillance the exact time when it started to spread is unclear. Likewise, it is unclear when and where it arose. In this work, we use phylogenetic analysis to investigate the origin of BA.2.86 and neutralization and virological assays to measure escape from neutralizing antibodies and other viral properties to give an indication of how different this variant is likely to be from recently circulating subvariants descended from XBB. We find that BA.2.86 likely evolved in Southern Africa. Despite the extensive genomic changes relative to other circulating variants, our data supports the notion that BA.2.86 is not substantially different from recent variants in escape from neutralizing antibodies or cellular infection.