November 2005: First implementation of sitemaps for Wikipedia deployed (Wikitech-l thread). Jens Frank and Ævar Arnfjörð Bjarmason wrote generateSitemap.php. Cron job set up. Sitemaps hosted at sitemap.wikimedia.org on benet. IRC discussion indicates a contact with Google at this time helped with the technical details.
April 2008: Migration of sitemap.wikimedia.org off benet.
July 2009: Brooke reports on private-l having a call with Nick Corman at Google. A sitemap for Commons was discussed. The discussion was inconclusive.
Around this time, Tim recalls sitemaps for Wikipedia being turned off at Google's request, because it was conflicting with their custom solution for wiki page discovery. Can't find any archive trace.
June 2015: sitemap.wikimedia.org was deleted. Nobody on the task knows when it stopped working, but it was certainly nonfunctional at that time.
November 2018: Sitemaps test by Ian Marlier. Following a recommendation from an SEO expert, an A/B test was set up with /sitemap paths of the relevant wiki domains being routed to sitemaps.wikimedia.org (note plural). Files were apparently generated with generateSitemap.php and uploaded manually.
