The word encyclopedia is derived from two Greek words meaning “a circle of learning.” The oldest known encyclopedia was written in Greece about 2,000 years ago. It’s no longer in existence. The oldest encyclopedia in existence was written in the 1st century by Roman scholar Gaius Plinius Secundus (Pliny the Elder); called Natural History, it consists of 37 volumes.
The largest ever encyclopedia is the 17th century Yung Lo Ta Tien encyclopedia. Written by 2,000 writers, it was bound in 11,100 volumes.
The first volume of Encyclopaedia Britannica was published in 1771, a year after Beethoven was born and 5 years before America declared independence. The latest version of Encylopedia Britannica is, obviously, available online where it competing in popularity with the open source Wikipedia.