Lectionary 150, designated by siglum ℓ 150 (in the Gregory-Aland numbering), is also known as Codex Harleianus. It is a Greek manuscript of the New Testament, on vellum leaves and one of four extant Greek lectionaries with explicit dates from before 1000.^[1]

The manuscript is written in compressed Greek Uncial letters, on 374 parchment leaves (35.2 cm by 26.7 cm), in 2 columns per page, 21 lines per page, with ornaments.^[1] The capital letters and nomina sacra are in red ink. The codex includes ten leaves of paper containing a series of Lessons from the Gospels, John, Matthew and the Luke lectionary (Evangelistarium). The image shows the text of John 1:18.

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.'^[2] It also contains musical notation.

According to the colophon it was written by a presbyter called Constantine.^[3] The manuscript came from Constantinople. In 1677 John Covel, chaplain of the English embassy in Constantinople, purchased this manuscript. It was shown by him to John Mill (1645-1707),^[4] in London.^[2] From Covel it was purchased – together with other manuscripts – by Robert Harley, Earl of Oxford.^[2]

It was collated by Bloomfield and examined by Woide.^[3]

The manuscript is often cited in the critical editions of the Greek New Testament (UBS3).^[5] It is not cited in UBS4.^[6]

The codex is now located in the British Library (Harley MS 5598).^[1]

Wikimedia Commons has media related to Lectionary 150.

• List of New Testament lectionaries
• Biblical manuscript
• Textual criticism