An Etymological Dictionary of the German Language/Annotated/folgen

folgen, verb, ‘to follow, succeed, result, obey,’ from the equivalent Middle High German volgen, Old High German folgên; compare Dutch volgen, Anglo-Saxon fylgan, folgian, English to follow, Old Icelandic fylgja; the verb common to West Teutonic and Scandinavian for ‘follow,’ which has supplanted the common Aryan verbal root seg (see sehen), Latin sequi. The origin of the cognates is uncertain. There are indications that the verbal stem is a compound; the first component may be voll; compare Anglo-Saxon ful-eóde, ‘he followed,’ Anglo-Saxon and Old Low German fulgangan, Old High German fola gân, ‘to follow.’ Consequently gehen (Old High German gên, gân) is the second part of the word. The composite nature of the word is supported by the fact that there are no old and widely diffused derivatives of the verb. It is true that the connection between the sense ‘to follow’ and the prefix voll has not yet been explained. —