Abdu'l-Baha's will charged Shoghi Effendi with constructing the Baha'i administrative order that Baha'u'llah's writings had outlined only in principle: local and national Spiritual Assemblies elected by secret ballot without campaigning or nomination, rising eventually to an elected Universal House of Justice. Shoghi Effendi treated this structure as itself a religious teaching, not merely an organizational convenience, and spent much of his guardianship establishing assemblies, drafting their electoral procedures and writing the constitutional documents that defined their authority.
He also directed the faith's systematic geographic expansion. The Ten Year Crusade he launched in 1953 assigned named individuals, the Knights of Baha'u'llah, to open specific unopened territories and islands to the faith, a campaign that more than tripled the number of countries with an organized Baha'i presence by its close in 1963. He developed the Baha'i World Centre in Haifa and Akka, acquiring land and building around the shrines of Baha'u'llah and the Bab and laying the terraces later completed as a pilgrimage and administrative site.
Shoghi Effendi died in London in November 1957 without having named a successor guardian, having, according to Baha'i understanding, no living relative eligible under the will's own conditions. The Hands of the Cause of God, a body of appointed believers he had raised up for exactly this contingency, guided the community until the Universal House of Justice was first elected in 1963, the body Baha'u'llah's Aqdas and Abdu'l-Baha's will had always intended as the faith's permanent head.