The Collins English Dictionary definition is:

Lineage n 1 direct descent from an ancestor, esp a line of descendants from one ancestor. 2 a less common work for derivation. [C14: from Old French lignage, from Latin linea LINE]

Burke’s Peerage and Gentry articles, whether online or in printed form, begin with the family name or title, followed by information on the current incumbent, then lineage where known.

The lineage starts with the earliest recorded ancestor and progresses chronologically. In Burke’s articles, the lineage often includes gems of historical commentary such as information on the origins of the family line, battles, allegiances and so on. For example:

SANDILANDS OF LAGGANMORE
ANDREW PATRICK SANDILANDS, of Lagganmore, by Oban, Argyll, b 20 Aug 1960.

Lineage–The family of Sandilands takes its name from the lands of Sandilands, Lanarks, which were confirmed to James of Sandilands by William, Ld of Douglas, 18 Dec 1348. The Chiefs of the name were Barons of Sandilands and later Barons of Calder, Midlothian, and are now represented by Ld Torphichen (see that title). The branch of which we treat was granted the lands of Middlerig, Lanarkshire, and Bold, Peeblesshire, by charter of King Malcolm IV (1153-65), but an established descent can only be traced from–

JAMES SANDILANDS of Middlerig and Bold, reputedly the 15th Laird; m Margaret, dau of Sir James Sandilands of Calder (see TORPICHEN, L.), by his 2nd wife Margaret Ker, and had issue,

JAMES SANDILANDS, of Middlerig and Bold, reputedly 16th Laird, living 1500; m Rachel, dau of John Dickson of Ormiston, Peeblesshire, by his wife Mary, dau of James Stuart, 1st of Traquair (see BURKE'S Extinct & Dormant Baronetcies, STUART–BARONS OF STUART AND EARLS OF TRAQUAIR), and had issue, with twenty-five other children,

• 1a (est s), reputedly 17th of Middlerig and Bold; m, and had issue,
• 1b James, reputedly 18th of Middlerig and Bold, disposed the lands of Bold to Sir John Stuart, later 1st Earl of Traquair, 16 June 24, still living 1646.
• 2a Gavin (9th child), of Lumford, West Lothian; m Mary, dau of Robert Wauchope of Niddrie, and had issue.
• 3a PATRICK (10th child), of whom presently.

Find out more about the structure of lineages.