Warsaw was important because of regular parliamentary conventions of the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania for the expected union.

Construction was led by the Italian Erazm Giotto of Zakroczym, with supervision from the Czersk Castellan and the Mayor of Warsaw, Zygmunt Wolski.

It was erected on a stone foundation and had three main rooms: a large heated dining hall, a chamber with a cocklestove, and a bedroom with an entrance to the basement.

He recorded this in Latin: ""Ne pontem sublicium superbo sumptu, atqe arte admirabili, a Sigmundo Augusto Rege fratre inchoatum, et a se post ejus mortem, consimili opere perfectum, repens vicina Suburbanorum male cantorum tectorum flamma, nec opina temore unquam corriperet correptumque in favillam redigeret.

Anna Jagellona Poloniae Regum, conjux, Soror, Filia, hoc Caterilli propugnaculi Sepimento lutissimo a fundamentis excitato muniendum curavit."

Paul Mucante 1595 Where he mentions that the bridge was started by the King and finished by his sister but is running a risk of fire by being made of wood.

Pierwej zawżdy szeląg nad potrzebę chował, A dziś i tenem przepił, bo, idąc do domu Najpóźniej, od przewozu nie płacę nikomu - Jan Kochanowski (1530-1584)