Here is a good link to a concise history of the (in)famous Codex Vaticanus, or simply 'codex B', an uncial manuscript variously dated from the 4th or 5th century, and often indirectly referred to in the margins of modern New Testaments as one of the "oldest and best" (!?) manuscripts which support some change or other to the traditional text.
Codex Faticanus: History
Codex Faticanus: History