Chronology of events:

For some events, the year is certain but the month and day are not. Example: We know only the year for the collections of Leeuwenhoek's letters published in Dutch during his lifetime.

For other events, the season or month are certain but the day is not. Example: Leeuwenhoek mentions that someone visited him "last month".

On the other hand, many events did indeed happen on the first day of a month. Example: public appointments to Delft's city offices took effect on January 1 of each year. Thus:

  • A date of January 1 in a given year may indicate that the year is certain but the month and day are not.
  • A date of 1 in a given month may indicate that the year and month are certain but the day is not.

Unless otherwise indicated, for events in England, the date given is Old Style, 10 days behind the Dutch Republic's New Style until 1700 and then 11 days behind.

Date
January 1, 1698 Published Onsigtbare Verborgentheden (Invisible Mysteries), Letters 38, 42, 43 (3rd)
January 1, 1698 Published A. van Leeuwenhoeks 41ste Missive, Geschreven aen (written to) de Koninklijke Societeit tot Londen
January 1, 1698 Visited by Tsar Peter the Great of Russia. Traveled to Antwerp.
February 20, 1698 Wrote letter of 1698-02-20 (AB 191) to Antonio Magliabechi
March 21, 1698 Govert Bidloo wrote to Leeuwenhoek about little animals in sheep's livers
April 17, 1698 Wrote letter of 1698-04-17 (AB 192) to Antonio Magliabechi
May 9, 1698 Wrote Letter 111 of 1698-05-09 (AB 193) to Members of the Royal Society
July 5, 1698 Appointed curator of the insolvent estate of Hendrick van Tol
August 14, 1698 Wrote letter of 1698-08-14 (AB 194) to Antonio Magliabechi
September 20, 1698 Wrote Letter 112 of 1698-09-20 (AB 195) to Anthonie Heinsius
December 17, 1698 Wrote Letter 113 of 1698-12-17 (AB 196) to Harmen van Zoelen
February 1, 1699 Wrote Letter 114 of 1699-02-01 (AB 197) to N.N.
February 28, 1699 Wrote letter of 1699-02-28 (AB 198) to Antonio Magliabechi
April 26, 1699 Wrote Letter 115 of 1699-04-26 (AB 199) to Harmen van Zoelen
June 9, 1699 Wrote Letter 116 of 1699-06-09 (AB 200) to Members of the Royal Society
June 23, 1699 Wrote Letter 117 of 1699-06-23 (AB 201) to Members of the Royal Society
August 5, 1699 Wrote Letter 118 of 1699-08-05 (AB 202) to N.N.
September 1, 1699 Wrote letter of 1699-09-01 (AB 203) to Hans Sloane
September 25, 1699 Wrote Letter 119 of 1699-09-25 (AB 204) to Members of the Royal Society
October 1, 1699 Wrote Letter 120 of 1699-10-01 (AB 205) to N.N.
October 16, 1699 Wrote Letter 121 of 1699-10-16 (AB 206) to Antonio Magliabechi
December 1, 1699 Received payment from city for duties with magistrate's court
January 1, 1700 Visited by Hans Sloane, his editor at Philosophical Transactions
January 2, 1700 Wrote Letter 122 of 1700-01-02 (AB 207) to Hans Sloane
January 14, 1700 Wrote Letter 123 of 1700-01-14 (AB 208) to Nicolaes Boogaert van Belois
May 20, 1700 Wrote Letter 124 of 1700-05-20 (AB 209) to Hendrik van Bleyswijk
May 20, 1700 Wrote Letter 126 of 1700-05-20 (AB 210) to Anthonie Heinsius
May 28, 1700 Hans Sloane wrote to Leeuwenhoek about translation problems and parasitic worms
June 2, 1700 Wrote Letter 125 of 1700-06-02 (AB 211) to Frederik Adriaan van Reede van Renswoude
June 14, 1700 Wrote Letter 127 of 1700-06-14 (AB 212) to Hans Sloane
June 16, 1700 Wrote Letter 133 of 1700-06-16 (AB 213) to N.N.
July 9, 1700 Wrote Letter 128 of 1700-07-09 (AB 214) to Hans Sloane
July 10, 1700 Wrote Letter 129 of 1700-07-10 (AB 215) to Anthonie Heinsius
July 19, 1700 Received letter from Hans Sloane with larvae to examine
July 24, 1700 Began series of observations of rams' testicles
July 27, 1700 Continued observations of rams' testicles
July 27, 1700 Wrote Letter 130 of 1700-07-27 (AB 216) to Hans Sloane
July 30, 1700 Concluded series of observations of rams' testicles
August 1, 1700 Wrote Letter 131 of 1700-08-01 (AB 217) to N.N.
September 7, 1700 Wrote Letter 132 of 1700-09-07 (AB 218) to Hans Sloane
October 26, 1700 Wrote Letter 134 of 1700-10-26 (AB 219) to Hans Sloane
December 25, 1700 Wrote Letter 135 of 1700-12-25 (AB 220) to Hans Sloane
January 4, 1701 cousin Lambrecht Huijchs Leeuwenhoek buried
January 28, 1701 Wrote Letter 136 of 1701-01-28 (AB 221) to Hans Sloane
February 9, 1701 Wrote letter of 1701-02-09 (AB 222) to Frederik Adriaan van Reede van Renswoude
April 8, 1701 Wrote letter of 1701-04-08 (AB 223) to the Mayors of Delft
April 15, 1701 Wrote Letter 137 of 1701-04-15 (AB 224) to Members of the Royal Society
June 21, 1701 Wrote Letter 139 of 1701-06-21 (AB 225) to John Chamberlayne
June 21, 1701 Wrote Letter 138 of 1701-06-21 (AB 226) to Members of the Royal Society
June 21, 1701 Wrote letter of 1701-06-21 (AB 227) to Hans Sloane
August 1, 1701 At age 68, his 50th publication in Philosophical Transactions
August 2, 1701 Wrote Letter 140 of 1701-08-02 (AB 228) to Members of the Royal Society
August 26, 1701 Wrote Letter 141 of 1701-08-26 (AB 229) to Frederik Adriaan van Reede van Renswoude
September 16, 1701 Hans Sloane wrote to Leeuwenhoek personally thanking him for the bequest of 26 magnifying glasses
November 7, 1701 Hans Sloane wrote to Leeuwenhoek expressing the Royal Society's thanks for the bequest of 26 magnifying glasses
December 6, 1701 Wrote letter of 1701-12-06 (AB 230) to Hans Sloane
December 6, 1701 Wrote Letter 142 of 1701-12-06 (AB 231) to John Somers
December 20, 1701 Wrote Letter 143 of 1701-12-20 (AB 232) to Members of the Royal Society
January 1, 1702 Published Sevende Vervolg der Brieven (Seventh Continuation of the Letters), Letters 108 - 146
February 9, 1702 Wrote Letter 144 of 1702-02-09 (AB 233) to Hendrik van Bleyswijk
February 14, 1702 Wrote Letter 145 of 1702-02-14 (AB 234) to Members of the Royal Society
April 19, 1702 cousin Cornelis Lambrechts Leeuwenhoek (1670-1702) buried
April 20, 1702 Wrote Letter 146 of 1702-04-20 (AB 235) to Karl von Hessen-Kassel
April 20, 1702 Wrote letter of 1702-04-20 (AB 236) to Karl von Hessen-Kassel
April 28, 1702 Wrote letter of 1702-04-28 (AB 237) to Members of the Royal Society
December 8, 1702 Wrote letter of 1702-12-08 (AB 238) to John Chamberlayne
December 25, 1702 Wrote letter of 1702-12-25 (AB 239) to Members of the Royal Society
February 5, 1703 Wrote letter of 1703-02-05 (AB 240) to Members of the Royal Society
February 26, 1703 Wrote letter of 1703-02-26 (AB 241) to Members of the Royal Society
March 3, 1703 Robert Hooke died

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