The Netherlands increased its land area by about 20% since the 17th century through reclamation:
Reclamation continues today for flood protection and development space.
Significant annexation: Duchy of Limburg (1839). Overseas territories acquired in 17th–18th centuries included the Dutch East Indies (now Indonesia) and Suriname.
Notable disputes: Zuiderzee (resolved 1932 by Afsluitdijk dam) and Scheldt Estuary with Belgium (ongoing since 19th century).
In summary, the Netherlands expanded through sea reclamation, annexations, and territorial dispute resolutions.