1340 Geert Grote born in Deventer
1365 John à Kempis (Thomas’ brother) born
1374 Sisters of Common Life established by Grote
1379/80 Thomas à Kempis (known as Haemmerlein or Hemerken) born in Kempen
1384 Grote dies; first house of Brothers of Common Life established at Zwolle
1387 Florens Radewijns (c.1350–1400) founds monastery at Windesheim
c.1392–9 Thomas à Kempis visits Windesheim; his brother sends him (with a letter of introduction) to Radewijns in Deventer, where he lives with the Brothers of Common Life and attends the chapter school of St Lebuin
1395 Windesheim Congregation founded (Constitutions approved by Pope Boniface IX), including communities at Marienborn, Nieuwlicht, Eemstein and Windesheim
1398 Foundation of monastery at Mount St Agnes, near Zwolle
c.1399 Thomas moves to Zwolle, yet the date of his arrival at Mount St Agnes is uncertain
c.1400 First convent established at Diepenveen (founded by Salome Sticken and John Brinckerinck)
1406 Thomas becomes a novice at Mount St Agnes
1407 Thomas’ solemn profession of vows; there are now twelve monasteries in the Windesheim Congregation
1413/14 Thomas ordained priest
1424 Earliest dated manuscript of Book One of the Imitatio Christi
1427 Earliest dated manuscript of all four books of the Imitatio Christi
1425–c.31 Thomas elected Sub-Prior (for the first time) at Mount St Agnes
1429–31 Mount St Agnes community chooses to live in exile rather than disobey a papal interdict imposed on the diocese of Utrecht
1431 Thomas stays with his brother near Arnhem
1432 John à Kempis dies
1441 Date of autograph manuscript
1448–58 Re-elected Sub-Prior at Mount St Agnes
1471 Thomas à Kempis dies
c.1471 First (Latin) edition of the Imitatio, printed in Augsburg
1511 Devotio moderna consists of eighty-four monasteries and thirteen convents