Archbishop Justin will travel to Sudan this weekend to inaugurate a 39th province of the worldwide Anglican Communion.
The service will be held in the nation's capital of Khartoum on Sunday.
Since the creation of South Sudan six years ago, the Sudanese Anglican church was controlled from Juba, the capital of South Sudan.
The province of South Sudan, which has a predominantly Christian population, requested the Anglican Consecutive Council (ACC) start a new province in Sudan.
The move has been in the works since April 2016 when the ACC sent a team to Sudan to check if a new province would be pliable.
The new Sudan province, which has mostly Muslim residents, is carved out of what was formerly called the Episcopal Church of South Sudan and Sudan.
Archbishop Ezekiel Kondo will be enthroned as the new leader of the province.
While in Sudan, Welby will also visit one of five dioceses in Sudan which has seen the most violence in the country's conflict. An office in Kadugli was destroyed years ago because of conflict, and the archbishop will celebrate the opening of a new one in its place.
After the ceremony, Welby will travel to Uganda and visit two refugee camps which house around 900,000 South Sudanese refugees.
Welby will be hosted by the primate of Uganda and will meet with government leaders.
The trip will be used as an opportunity to bring the plight of the refugee crisis to the international community and encourage and reconciliation.
