Lectionary 150, designated by siglum ℓ 150 (in the Gregory-Aland numbering), is also known as Codex Harleianus.

The codex includes ten leaves of paper containing a series of Lessons from the Gospels, John, Matthew and the Luke lectionary (Evangelistarium).

It is one of the most beautiful lectionary codices, with a scribal date of 27 May 995 A.D. 'It is a most splendid specimen of the uncial class of Evangelistaria, and its text presents many instructive variations.

In 1677 John Covel, chaplain of the English embassy in Constantinople, purchased this manuscript.

[2] From Covel it was purchased – together with other manuscripts – by Robert Harley, Earl of Oxford.