Ascension of Abdu'l-Bahá is a Bahá'í holy day marking the 1921 passing of Abdu'l-Bahá, the eldest son of Bahá'u'lláh who served as the appointed successor and authorized interpreter of his father's teachings. Bahá'ís regard him as a model of humble service and selfless devotion, and he is remembered for expanding the Bahá'í Faith internationally and for his extensive writings and talks explaining Bahá'í principles to audiences worldwide, including during travels through Europe and North America. This day is typically observed with prayer gatherings and reflection rather than celebration.