The very first St. Bavo Church was mentioned yet in 1245 and was already considered prominent, among other things because of its belfry. Influential people like Arnoud van Sassenheim acted there as priests.
The direct predecessor of the present church consisted from a choir, nave, transept and a west tower which was tall enough to be used as a watchtower for firemen. This tower had a peak made of slate and probably also lead, and possibly also a small lantern. It was provided with a weathercock and a clock (1402) with a bell and an indicator.
In the tower there hanged 7 bells, including:
- the Salvator (1440 / ± 4600 kg)
- the Maria (1375 / ±1700 kg)
- the Baef (in 1440 enlarged for Salvator)
- the hour bell
In 1423/1433 a richly decorated Font Chapel was built against the west side of the church with a charming baptismal font in it with a wrought-iron tap. In the old nave (the new choir was in the meantime complete) the glazing was constantly embellished. In those times there probably existed no further building plans.
The Dutch word ‘viering’ originates from the word ‘vierinc’ (‘vierdinc’, ‘vierdonk’) = square space formed by the crossing of the nave and the transept.
The four big columns and the stellar vault are property of the municipality of Haarlem; one day they formed the foundation of the crossing tower.
‘When the year MCCCCC (1500) came, Jacob Engbrechts/Dirk Klaesz. de Vries/Jan Bruijn Harmann were the church wardens who commissioned in that year the construction of the vaulting with the two big arches’.
The tower contained at the time:
- a clock with 1 hand, a golden finger (creation / beginning of the time) and a cloud (representing Christ/end of the time)
- a rope to the Bell Roelant (5500kg), founded in 1503 by G. van Wou, with the Belfry of Gent being the example.
The original design for the stone tower was made by Cornelis de Wael in 1502. It is still visible on a pattern painting of Pieter Gerritsz from 1518.
Upon his death the work was taken over in 1505 by master Anth. Keldermans. The stone tower seemed to be too heavy for the crossing pillars and the north-east pillar sank (still visible); some gravestones around it cracked.
Between 1514 and 1517 the tower was then broken off again. Then Michiel Bartszn. designed a wooden crossing tower covered with lead.
Master Jacob Symonsz from Edam carried out the project in the years 1518-1520. Instead of two original lanterns the wooden tower received three lanterns. The stone planning of De Wael/Keldermans stayed preserved as a fundament for the new crossing tower.
The dimensions are: 35 to 40 m height; an ‘onion’ of 3m high and 3m in diameter; a cross of 550 kg, a cock of 65 kg and a carillon of more than 10.000 kg (47 bells). The weight of the leaden cover comprises about 85.000 – 100.000 kg.