Mosta was originally an extension of the Mdina Parish, before being re-assigned to the newly founded Naxxar Parish in 1436. In a report of his Pastoral visit in 1575, Monseigneur Dusina refers to Mosta as a parish, but this status was only officially proclaimed in 1608.
This called for the immediate building a new church on the plans drawn by Tommaso Dingli.
It was officially consecrated by Bishop Pellerano on the 7th April, 1744.
By the 1830s Dingli's church was no longer adequate for the growing Mosta population, so a much larger and ambitious project was conceived: the Rotunda, based on the plans of George Grognet de Vasse.
A French expatriate, Grognet chose Rome's Parthenon as a model for his inspiration.
The builder Anglu Gatt, known in town as Mastr' Ang, was originally from Zejtun. Mosta residents, at that time not more than 1500, actively contributed and participated in the building of the magnificent Rotunda. It was completed in 1871 after 27 years of hard work, and is now an icon of the town itself.
Domes are particularly demanding structures since they constitute a self-supporting structural element of architecture that resembles the hollow upper half of a sphere. The Rotunda is the third-largest unsupported dome in Europe and the ninth-largest in the world with a diameter of 36.6 metres (120 feet).
Grognet inspected samples from quarries all over Malta in order to chose the most durable type of stone available.
His choice was a quarry known as Ta' Vnezja, at the outer periphery of Mosta, in the immediate proximity of what later became the gate of a WWII RAF airfield in Ta' Qali.
The church risked destruction due to its immediate vicinity to this military outpost epitomised by a bombing raid on the 9th April, 1942. A German aircraft jettisoned a number of bombs over and around the church causing one to break through the ceiling and smash into the floor below.
The incident is considered a miracle since the bombs had not been primed and could not explode, leaving the congregation present terrified but unscathed.
The feast of Saint Mary the Assumption, to whom the church is dedicated, is celebrated annually on the 15th August.
Another well known feature related to popular and religious culture is the Good Friday procession. There are two band clubs and two fireworks factories in Mosta.
All these societies add much life and colour to the various events that dot the socio-parochial year.