 Sannidal (together with Skåtøy) was merged with Kragerø January 1, 1960.Sannidal at the time had 2,604 inhabitants.Until 1857 the name was written "Sannikedal", in the period 1857–88 "Sandøkedal", in the period 1889–1917 (again) "Sannikedal", from 1918 onwards "Sannidal".