Since the seventeenth century members of the Kruys family have been active in the Dutch National Cabinet, town councils, Royal Netherlands Navy command and the international business and trade community.

[2][3] The genealogy of the Kruys family has been recorded since 1914 in the Dutch Patriciate Blue Book (Blauwe Boekje), published by the Centrum voor familiegeschiedenis in The Hague.

The Kruys family archives are kept at the Dutch Institute of Military History in The Hague and the Historical Museum in Vriezenveen.

[3] A third grandson, naval lieutenant Gerhard Rudolph Kruys (1913–1941), died during World War II at the age of 28.

[1][11] Gerhardus' half brother, Hendrik Kruys, was a successful trader and member of the ‘Rusluie’, a community of Dutch expats living in the city of Saint Petersburg in Russia between 1720 and 1917.

[13][14] According to a description in the diary of Hendrik's uncle Jacob Kruys (1812–1852), the 2,400 kilometres journey by covered wagon from Vriezenveen to Saint Petersburg led through Osnabrück, Berlin and Riga, and took 15 days at the time.

[15] In 1868 Hendrik travelled to Saint Petersburg by train, where he became an apprentice at the Dutch firm Engberts & Co, selling linnen.

In 1884 Hendrik started his own trading house, ‘Java’ on Grosse Morskaya 38, where he sold Dutch Coffee and cocoa, as well as tea, spices, liquor and other products.

[16] In his diary (archived at the Vriezenveen Historical Museum), Hendrik recorded many events and developments, including the beginning of the first Russian Revolution of 1905: "A lot of commotion in the city and people shot by soldiers.

[1] During World War II, Willem Jan was commander lieutenant of the Dutch Destroyer HNLMS Tjerk Hiddes, performing convoy escort duties in the Indian Ocean before joining the US 7th Fleet (1942), stationed in the Port of Fremantle, Western Australia.

[17] In 1942 HNLMS Tjerk Hiddes embarked on a mission to remove Allied troops stranded on Timor in enemy territory.

[18] On 9, 15 and 18 December, the Tjerk Hiddes made three voyages to Timor and evacuated over a thousand Australian Forces, Dutch troops and civilians to Darwin in Australia.

[17] Willem Jan was awarded the Legion of Merit by President Roosevelt: "By his fearless determination, excellent judgment, and outstanding professional ability throughout this period, he brought to a successful conclusion an extremely difficult and perilous mission.

[20][21] He was closely involved in the 1949 Dutch-Indonesian Round Table Conference about the transfer of sovereignty of the Dutch East Indies.

On 18 November 1953, Willem Jan became the first captain of the new Zeven Provinciën class light cruiser HNLMS De Ruyter.

[1] During World War II, Gerhard served on the HNLMS K XVII, a submarine of the K XIV-class, built by the Rotterdam shipyard Wilton-Fijenoord as a patrol ship to protect the Dutch East Indies.

[10] More than 40 years later, on May 2, 1982, the wreck of a submarine found on the seabed off the coast of Tioman Island in Malaysia was identified as the HNLMS K XVII.

From 1781 tot 1789, Jan and his brother Johannes Kruys (1769–1806) worked with their father at the family business in St Petersburg.

In one of his entries he describes how in 1795, 2000 cavalry of the French Revolutionary Army rode into Amsterdam, where he lived at the time, marking the proclamation of the Dutch Batavian Republic.

He wrote: “A tree of liberty was planted in front of the town hall and people were out and about and cheering.” (transcription: Erik Berkhof, Frans Harwig)[3] Jan was married to Anna Broers (1772–1793), who died in childbirth.