Answer:

shah

Answer	Crossword Clue
SHAH	Ayatollah predecessor
SHAH	Former Iranian ruler
SHAH	Onetime Iranian ruler

SHAH	Onetime ruler of 23A
SHAH	Bygone ruler
SHAH	Walton of Wal-Mart
SHAH	Monarch until 1979
SHAH	Ruler with a palace in Tehran, once
SHAH	... mat (Arabic phrase meaning "the king is defeated" that led to the word "checkmate")
SHAH	Jahan's title
SHAH	1979 exile

SHAH	Iranian king
SHAH	Reza Khan, for one
SHAH	Persian bigwig
SHAH	Ruler until 1979
SHAH	Persian for "king"
SHAH	Peacock Throne occupant
SHAH	Persian ruler
SHAH	It means "king" in Persian

SHAH	Former sovereign of Iran
SHAH	Persian sovereign
SHAH	Former Persian ruler
SHAH	Exile of 1979
SHAH	Taj Mahal builder .. Jahan
SHAH	Former Persian potentate
SHAH	Old ruler
SHAH	Persian king

SHAH	Persian title
SHAH	Bygone Iranian despot
SHAH	Deposed Iranian ruler
SHAH	Deposed ruler
SHAH	Former Mideast leader
SHAH	Old monarch
SHAH	Bygone Mideast ruler
SHAH	Former Iranian monarch

SHAH	Ayatollah's predecessor
SHAH	Iranian ruler until 1979
SHAH	Old Iranian VIP
SHAH	1979 Iranian exile
SHAH	Bygone Mideast despot