He was schepen, hoogheemraad of the Hoogheemraadschap van Rijnland and a counsellor of the States of Holland and West Friesland at The Hague.

They had five children:[6] In 1617 Cornelis Bicker and his wife settled at Singel 130 in Amsterdam, in a canal house which his family sold in 1767.

[9] In 1632 he bought the Swieten estate and manorhouse from Hugo Cuyk van Mierop - from these he later derived his noble title.

[13] During the 1640s, the republican elite of the province of Holland, the brothers Cornelis, Andries,[2] Jacob and Jan Bicker,[14] Jacob de Witt and the brothers Andries[14] and Cornelis de Graeff advocated an end to the Eighty Years' War with the Kingdom of Spain and a reduction in land forces.

During the 1640s, the influence of Andries Bicker, his family and the city grew even greater as the end of the Eighty Years' War drew nearer.

[18] After the peace treaties and the reduction of the land forces, the political opposition to the House of Orange and in particular to the new stadtholder William II, who wanted to make the city of Amsterdam docile in 1650 by means of a coup d'etat, deepened.

Gerard set off for Amsterdam immediately and after receiving the news Cornelis and Andries together with burgomaster Joan Huydecoper van Maarsseveen raised the bridges, shut the gates and deployed artillery.

Cornelis Bicker also appears as a captain in a 1638 militia group portrait by Joachim von Sandrart, commissioned by the Kloveniersdoelen to mark the visit of Maria de Medici and now in the Rijksmuseum in Amsterdam.

[27] and threw his work in the Amsterdam Vroedschap and as one of the founders of the East India Company, he was able to launch the careers of his sons, grandchildren and nephews.

Cornelis' oldest brother Andries Bicker ruled the city administration for a long time and was mainly supported and carried by him and their other two brothers Jacob and Jan Bicker, his uncle Jacob Dircksz de Graeff and his cousin Cornelis de Graeff.