Educated at Bedford School, he obtained a scholarship at Trinity College, Cambridge in 1852, receiving a BA degree in 1855,[1] followed by a distinguished academic career.
The Maitland essay of 1861, on Christian Missions during the Middle Ages, was recast as Apostles of Medieval Europe (1869), and was the first of a series of volumes on missionary history.
Eventually he accepted the post of warden of St. Augustine's Missionary College, Canterbury, in 1880, and held it til his death.
He died at St. Augustine's College, after a long illness, on 19 October 1902, and was buried in St Martin's churchyard, Canterbury.
To missionary history he contributed The Conversion of the West (4 vols 1878) and St Augustine's, Canterbury: its Rise, Ruin and Restoration (1888); and he wrote on missions in the Encyclopædia Britannica (9th ed).
Maclear also published, with several devotional books, An Elementary Introduction to the Book of Common Prayer (1868) and The Baptismal Office and the Order of Confirmation (1902), in both of which he collaborated with Francis Procter; he edited portions of the Cambridge Bible for Schools; and contributed to Smith's Dictionaries of Christian Antiquities and Christian Biography, and to Cassell's Bible Educator.