When the captivity of the Popes in Avignon was beginning in the West, and the Copts were persecuted by the Mamluk sultan in the East, the document Theodorich de villa Boneti was mentioning Boian for the first time as the center of the diocese of Târnava Mică. The settlement became important for the kings from the eastern side of the Carpathians when around 1488 King Mathias Corvinus donated several villages as fiefs which were ruled until the reign of Alexandru Lăpușneanu. Signs showing that the settlement belongued to Cetatea de Baltă and implicitly to its ruling power can be seen inside the fortified church, on the northern part of the nave, close to the cornice of the roof, but especially on the belfry where a bull head with the stars between the horns appear depicted on a relief placed on a circular plate. These are the only indisputable examples of the Moldavian heraldry in Transylvania.

The hall church built of stone is made of a single nave and a rectangular altar. The first fortified element of the evangelic church from the beginning of the 16th century, was the star vaulted choir raised by a defense level on strong arcades supported by consoles. Machicolations for throwing pitch were hidden under each arcade, the walls being provided with crenels. Probably the polygonal walls of the apse were replaced with a straight one supported by an axis on the inside and by a buttress on the outside. The date written on the chancel arch – 1506 – refers to the year when the choir was strengthened, rather than to the year it was built. The tabernacle dates from the same year. A polyptych altarpiece from 1430 – 1440 existed here, whose reliefs are related to the workshops in Slovakia. The actual Baroque altar dates from the 18th century, together with the pulpit painted by Ștefan Valepagi from Mediaș. The fragments of paintings which can be seen on the northern part are most likely from the previous century, because of the simmilarities with the paintings from the church in Mediaș, dating from the second half of the 15th century. 

The star vault of the nave lasted until 1900 when it was replaced with a stucco ceiling. 

Along with the fortification of the choir, a surrounding curtain wall with an octagonal precinct and three towers were built in the first half of the 16th century. The six meter high walls are provided with crenels and supported by buttresses. The entrance was through the massive square section tower which functioned as a belfry and was provided with a portcullis.