Complex sentence: Eachann Mac Goraidh MacAlasdair (anglicised: "Hector MacGorrie MacAlester"), he became 6th of Loup, Chief of Clan MacAlister in 1636.
Split into simpler sentences: Eachann Mac Goraidh MacAlasdair (anglicised: "Hector MacGorrie MacAlester"), was the 6th of Loup, Chief of Clan MacAlister. Hector MacAlester became Chief of Clan MacAlister in 1636.