Till 16th century Wrsaw did not have any solid bridge on Vistula (Wisla) river and king Zygmunt August decided to build one and so he contracted ERAZM FROM ZAKROCZYM.
Erazm was a talented Italian architect, but we don't know much about his life. His ancestors settled in Polish town Zakroczym, not far from Warsaw, in the beginning of 16th century.
He used to sign himself "Erasmus Cziotko, fabrikator ponlis Varszortensis" which could be a Polish version of and Italian name Giotto, the family from Florence, famous architects.
In 1568-1573 the construction works proceeded, but the king did not see the final opening, which took place already 9 months after his death.
The bridge was built of huge oak underwater posts and pine overwater piles, with 22 spans and 15 piers, it was 6m wide (20 feet) and 500m (1640 feet) long. It was the biggest and longest bridge in Europe of that time.
It was a huge success of engineer's genius, as the river was big, wide, whimsical and frozing in winter time. Erazm has become a honourable citizen of Warsaw in appreciation of this triumph.
The bridge had to be cared well, maintained and repaired every year. It survived 30 years, till 1603, when it finally collapsed under the pressure of spring flood and drift-ice. The Warsaw inhabitants had to wait for the next solid bridge over 250 years - untill 1864.

The photo shows the miniature of bridge reconstruction, displayed in the Historical Museum of Warsaw.
It can be also seen on the oldest Warsaw picture, dating from 1573 and on some later ones.

http://www.varsovia.pl/varsovia/index.php-frame=main&mapa=0&item=2769&top=2742.htm
http://pl.wikipedia.org/wiki/Most_Zygmunta_Augusta