He was born in Ponte Tresa or Mesanzena in 1531 and until 1555 he was in the service of Gian Giacomo de' Medici (1495-1555), Marquis of Marignano (the present-day Melegnano), with whom he had the possibility of studying mathematics and architecture (according to what Ramelli himself wrote).
This Medici, also known as Gian Giacomo 'il Medeghino', a condottiere , received the Marquisate of Marignano around 1532 from Francesco Sforza II, Duke of Milan, the city from which he had been banished due to his ambition. He also lived in Frascarolo, Musso and Gravedona on the Lake of Como.
It is also possible that the young Ramelli had accompanied him on some of his military adventures (such as the War of Siena).
Ramelli then moved to France where he worked in the service of Henry of Anjou (1551-1589), king of France from 1574 with the name of Henry III, son of Henry II and Catherine de' Medici. Henry II, at the centre of the religious struggles in sixteenth-century France, after having promoted the massacre of the night of St. Bartholomew (23-24 of August 1572) during which the Calvinists were exterminated, also in 1572 lay siege - unsuccessfully - to La Rochelle, the stronghold of the Huguenots. Ramelli took part in this siege in the role of engineer, perhaps accompanying a contingent of 4.000 Italian soldiers commanded by the Venetian, Filippo Strozzi, who had conducted military campaigns in the same places and during the same period, as had Gian Giacomo Medici. Ramelli, during an explorative mission at the Atlantic port of La Rochelle, was seriously wounded and captured, although thanks to the intervention on the part of the Duke he was soon released.
With the ascent to the throne of Henry III the engineer consolidated his position at court and decided to publish his studies and projects. These were collected together in the volume entitled The diverse and artifactitious machines of captain Agostino Ramelli: this was a ponderous work in folio, published in Paris in 1588, in which there are 194 plates accompanied by a text in Italian and French and which presents his congenial inventions, part of which imaginary. There are: 110 pumps or mechanisms for raising water, 25 mills, 10 cranes, 7 mechanisms for hauling heavy structures, 4 caissons for the drainage of ditches (and moats!), 4 fountains, 15 bridges for the crossing of ditches/moats, 14 devices for breaking through enemy defences and, finally, devices for launching cannon balls and also trabuches (kinds of catapults). This work is a classic of Renaissance engineering and exerted a considerable influence with regards to the development of European mechanics during the successive decades.
The volume describes the most diverse machines, among which a wheel with a vertical axis for the 'raising' of water (similar to the one designed by Leonardo da Vinci), a war machine capable of moving while submerged, mills and hydraulic wheels.
Perhaps his most well-known project is his 'book wheel', a rotating and multiple book-rest, allowing the easy and contemporary reading of more than one text. It offered its user the possibility of having various books on hand, maintained in an horizontal position by means of a complex system of toothed wheels, in such a way that the books will not fall, nor will they move from the place where they are put: in fact they will remain always in the same state, and they will represent themselves always before the reader in the same manner they have been placed above its boards, without that it should be necessary to bind them, nor hold them with any thing . To many people this mechanism has seemed to be the forerunner of hypertextual reading: that is, what you are doing in this very moment.
One continued to have reports about him: in 1590 when Filippo Pigafetta (1533-1604) affirmed that Paris, under siege, was defended with the help of Captain Agostino of Lugano . The last document found which deals with him is a legal paper dated 1608 with his signature and that of his wife. We have no report concerning his death.