The solemn liturgy will be serviced in the open air at the ancient basilica of Pliska.
The service is scheduled to start at 9:30 a.m.
Today the Bulgarian Orthodox Church commemorates Boris I of Bulgaria at a ceremony also marking the 1,145th anniversary since the establishment of the Bulgarian Orthodox Church (March 4, 870) and 1,150 years since the Christianisation of the Bulgarian nation.
The reign of Boris I was marked with significant events that shaped Bulgarian and Slavic history, such as the Christianisation of Bulgaria.