In 1078 King William used Gundulf's skill in the construction of the White Tower: the keep of the Tower of London, he was described as "competent and skilled at building in stone and was the principle overseer and surveyor of the White Tower of London"; also the castle at Colchester which was started around 1080. Colchester is attributed to Gundulf on the basis of the similarity in plan and design to the White Tower.
In 1078, King William utilized Gundulf's expertise in constructing the White Tower: the keep of the Tower of London; he was noted as "capable and proficient in building with stone and served as the primary supervisor and planner of the White Tower of London"; also the castle at Colchester which began around 1080. Colchester is attributed to Gundulf based on similarities in design and layout to the White Tower.