Houla (in Arabic: هوله), is a plural Arabic term for Houli (in Arabic: هولي), which "migrant Arabs"
Little is known about the Arab migrants who settled on the Iranian coast between Bushehr and Lengeh in the late 1500s. They were a disparate group of small tribes of sailors, traders, fishermen, pearl divers, and cultivators. Although they were all referred to as the Bani Hula, they were not a uniform group. In fact, they were each other's fiercest competitors for access to the pearl banks.
— The Persian Gulf: The Hula Arabs of The Shibkuh Coast of Iran by Willem Floor
The most recent influx of the Hola to the now known as GCC countries is during the 1960s. Iran under the Shah was strict regarding different ethnic groups and maintained censuses on them. Most of the Hola families were exiled from various ports and villages of Iran. One inviting country was Bahrain, which had a need for more Sunni Muslims as the country was mainly Shia and was ruled by a Sunni family that came from Saudi Arabia. It was also a country that had a fairly large Hola community that existed on the island beforehand. Though there was a difference between the variety of people that had come during different times, the term “Hola” began to be used generally for all Sunni Muslims that had connections with Iran, especially after the Iranian Revolution, which brought about anti-Shia tensions to the GCC nation states, uniting those that were Sunni. You will mainly hear this term used in Bahrain, though Oman and the UAE has a large number of these families living among them. The Hola had a degree of self-rule with a number of emirates (Arabic: see Arabic article) in the south of Iran until the 20th century. Following the ascent of the Pahlavi Dynasty, there was a diminution or abolition of the local ruling families' privileges as elsewhere in Iran.
Most of the Huwala families lived in the urban centres of the Persian Gulf states and established themselves as trading business families, making use of their networks across the Persian Gulf. In the Bahraini city of Manama, many settled in the neighbourhood of Awadhiya.
Zur is a reasonably large town which is fortifies in the local manner and which has some pieces of artillery. it is inhabited by a tribe of Huwala called Qawasim these have been in earlier times subject to the imam of Muscat but they do not recognise his authority any more
— Baron van Kniphausen, The Blood-red Arab Flag: An Investigation Into Qasimi Piracy, 1797-1820 By Charles E. Davies, p.173