I have translated and edited the first edition of Louis de Gaya's work L'Art de la Guerre from 1677. It is very much an instruction book for officers and men of all ranks in how to carry out their duties, but it does include sections on the infantry, cavalry and artillery, as well as infantry drill, plus some information on tactics and the defence and attack of fortresses. As a former officer in the regiment Champagne, it obviously concentrates on French practice in the 1670s. It is attached below as a PDF (just click on the link) for anyone who would like to read it. Feel free to download it as well for your own use. I would welcome any feedback.

Gaya's The Art of War

Apologies to anyone who tried to use the link, I forgot to add access to anyone! It should work fine now.