Willem Klein, also known as Wim Klein, was a Dutch mental calculator renowned for his extraordinary ability to perform complex calculations at a remarkable speed. Born on December 4, 1912, in Amsterdam, Klein's mathematical prowess was evident from a young age. Despite his initial pursuit of a medical degree, he ultimately embraced his passion for mathematics and gained recognition for his exceptional calculating abilities.Klein's remarkable talent was showcased when he calculated the 73rd root of a 500-digit number in a mere 2 minutes and 43 seconds, a feat that earned him a place in the Guinness Book of Records. His exceptional skills led to international recognition and opportunities to perform at prestigious events and institutions, including the Mathematisch Centrum and CERN.Tragically, Klein's life was marked by personal hardships, including the loss of his mother, the capture and death of his brother during the Holocaust, and his own struggles with his sexual orientation. Despite these challenges, he continued to pursue his passion for mathematics and mental calculation.Klein's legacy lives on through his impact on the field of mental calculation and his inclusion in popular culture, with neurologist Oliver Sacks referencing Klein's unique perspective on numbers. His story continues to inspire mathematicians and enthusiasts of human calculators, leaving a lasting impression on the world of numerical savants.Klein's untimely and unsolved murder in 1986 shocked the world, leaving behind a legacy of exceptional mathematical talent and unanswered

Willem Usselincx (1567 – c. 1647) was a Flemish Dutch merchant, investor, and diplomat, renowned for his pivotal role in drawing Dutch and Swedish attention to the New World's significance. Born in Antwerp during the tumultuous period of the Eighty Years' War, Usselincx witnessed the city's transformation from a prominent harbor to a city of religious and political upheaval. Following the capture of Antwerp by the Spanish in 1585, Usselincx relocated to the Republic of the Seven United Netherlands, where he championed the establishment of the Dutch West India Company. His vision extended beyond commercial interests, aiming to create a new society in the Americas. Usselincx's influence also extended to Sweden, where he collaborated with Peter Minuit to establish the Swedish South Company, ultimately contributing to the founding of New Sweden, the first Swedish colony in the New World. Despite facing financial turmoil from unsuccessful investments, Usselincx's enduring legacy lies in his pioneering efforts to shape European colonization and trade in the Americas.

Willem Verhulst, also known as Willem van Hulst, was a key figure in the early history of the New Netherland colony in the 17th century. Little is known about his life before and after his time as the provisional Director of the colony. He sailed from the Netherlands in 1625 and oversaw the decision to establish Fort Amsterdam, the main fortress, and town on the tip of Manhattan Island, which eventually became the first permanent European settlement in what is now New York City. Verhulst's tenure was short-lived, as he was quickly replaced by Peter Minuit. He returned to the Dutch Republic and brought back news of the colony's progress, including the purported purchase of Manhattan from the natives for goods valued at 60 guilders. The debate over whether Verhulst or Minuit executed the purchase remains unresolved. Despite the obscurity surrounding his role, Verhulst's influence on the early history of New Netherland is notable.

Wim Slijkhuis, born on January 13, 1923, was a renowned Dutch athlete, known for his exceptional middle-distance running abilities from 1939 to 1954. He gained international recognition after World War II, earning a silver medal in the 5000m at the European Championships in Oslo in 1946. Slijkhuis also participated in the 1948 Summer Olympics in London, securing a third-place finish in the 5000m and narrowly missing out on a medal in the 1500m event. Notably, he clinched the 1500m title at the 1950 European championships in Brussels. Slijkhuis' remarkable career saw him compete not only in Europe but also in New Zealand, South Africa, and the United States, where he became the first non-American to win the US title over one mile. Despite clashes with Dutch Athletics Federation officials, Slijkhuis left a lasting impression with his smooth running style, earning praise for his "Poetry of motion." He retired in 1954 due to injuries and passed away on June 28, 2003, leaving behind a legacy of eleven national titles and thirty Dutch records.

Willem Janssen, born on July 4, 1986, is a well-known Dutch professional football official and former player, renowned for his role as a central defender. Having debuted professionally for VVV-Venlo during the 2004–05 season, he subsequently joined Roda JC in 2007. Notably, in November 2010, Janssen's transfer to FC Twente was announced, marking a significant career move. His talents also led to a loan spell at FC Utrecht in August 2013. After retiring from playing, Janssen transitioned into a pivotal role as the technical director of VVV-Venlo in July 2022. Throughout his career, Janssen has garnered notable achievements, including winning the Johan Cruijff Schaal with Twente in 2011 and being named in the Eredivisie Team of the Month in August 2021. His contributions to the football world continue to be recognized and celebrated.