Geomundo Incident
Claiming to block Russia’s southward advance, the Royal Navy occupied the island of Geomundo without Korea’s consent, leaving after two years through Qing mediation.

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Chafing under Qing interference after the Gapsin Coup, Korea looked to Russia (a treaty in 1884 and rumours of a secret pact). Britain, Russia’s great rival, seized Geomundo in 1885 and built batteries and barracks, calling it Port Hamilton.
When Qing obtained a Russian pledge not to take Korean territory, the British left in 1887. The crisis exposed the great-power rivalry over the peninsula, prompting the German vice-consul Budler and Yu Gil-jun to propose Korean neutrality.