Population Migration / Travel
"Having grown somewhat distant from their brothers, the elves bearing the Shadow mark, those who would one day become House Phiarlan as we know them today, left Aerenal and settled in Khovaire, living among the human populations there."
The History of the Elves by Professor Zeldyr of Morgrave University
House Phiarlan leaves Aerenal to relocate among the humans of Khorvaire. A situation that largely resulted from feelings leftover from the the destruction of the House of Vol.