A possible descendant of Lachlann's was one "Lacclannus mcmuredhaich archipoeta", who witnessed a charter of Aonghas of Islay, son of the last member of "Clann Domhnaill" to be recognised as Lord of the Isles. Other members of the MacMhuirich family, possibly one or two, composed poems of Aonghas's murder that are preserved in the "Book of the Dean of Lismore". From about the 1490s and onwards, members of the family are also recorded as clergymen (and possibly as early as 1432, if the "John Muaritti" recorded in the Apostolic Camera is indeed a "MacMhuirich"). Following the collapse of the Lordship of the Isles, the MacMhuirich family appears to have been chiefly employed by the chiefs of the MacDonalds of Clanranald ("Clann Raghnaill"). The earliest poet of the MacMhuirich family on record is Niall Mór MacMhuirich ("c."1550-"c."1613). A member of the family was the "seanchaidh" (story-teller and genealogist) who authored much of the "Books of Clanranald", which date to the 17th and early 18th centuries. One of these books, the so-called "Red Book", is best known for its account of the history of "Clann Domhnaill", which was composed by Niall. The other book, the so-called "Black Book", is more of a miscellaneous compilation, although it contains a version of Niall's history composed by a member of the Beaton family, another learned family of professionals that was once centred in the Hebrides. Other noted members of the family were Cathal MacMhuirich ("fl."1625) and Niall MacMhuirich ("c."1637–1726), the last fully competent practitioner of the family and who was still working in the first quarter of the 18th century. In the first part of the 16th century members of the family are also recorded as Harpers, and one "John oig Mc murcquhie leiche in Ilay", a physician, is recorded in 1615. The last of the family to practice Classical Gaelic poetry was Domhnall MacMhuirich, who lived on South Uist, as a tenant of Macdonald of Clanranald, in the 18th century.