[glenc (Glen)]

About 75 deep sky objects were known before Messier started his catalogue according to the Discovery Table of Deep Sky Objects
http://www.seds.org/messier/xtra/history/dis-tab.html


The first person to discover more than 3 objects was Giovanni Battista Hodierna (April 13, 1597 - April 6, 1660).

Hodierna's catalog of nebulous objects includes independent rediscoveries of the Andromeda Nebula (M31) and the Orion Nebula (M42) and at least 9, but probably 14 and perhaps 16, own original discoveries: M6, M36, M37, M38, M41, M47, NGC 2362, NGC 6231, NGC 6530 (the cluster associated with the Lagoon Nebula M8), the Alpha Persei Cluster (Mel 20), probably M33, M34 and NGC 752, and (possibly) NGC 2451, as well as two further possible discoveries of NGC 2169 and NGC 2175 for which the identification is very unsafe. Also in this work, he created the first preserved drawing of the Orion Nebula.
http://www.seds.org/messier/xtra/Bios/hodierna.html