Yule's study of the prehistory of Oman began from 1982 to 1987 as a volunteer at the
Deutsches Bergbau-Museum in Bochum together with
Gerd Weisgerber. Yule focussed on the cataloguing of the metal hoard find from
Ibri-Selme (and others as well), which he published with
Gerd Weisgerber. This typological study catalogues the largest hoard of metallic artefacts to occur in the Near East. Stashed in an
Umm an-Nar period communal tomb, these date to the
Early Iron Age. In 1987 Yule began his
habilitation on the site of
Samad al-Shan which sheds light on the late pre-Islamic, protoliterate
Late Iron Age population of central Oman. It comes into view as early as 200 BCE and may continue 200–400 years, prior to the arrival of
Islam in Oman. After 2006 he raised the chronology of the Samad Late Iron Age. The cemetery site, Samad, yields eastern Arabian artefacts of different periods. New excavations were intended to better date the Early Iron Age. New was the introduction of alphanumeric abbreviations for site and artefact classes to enable computer processing. In the mid-1990s Yule and Weisgerber mapped and studied the tower tombs of
Jaylah in the eastern part of the
Jebel Akhdhar, which may date to the
Bronze Age Umm an-Nar Period mid-late 3rd millennium BCE. Yule sought unsuccessfully late antique habitation in his excavation at the oasis site of Izki/al-Yemen. Yule updated his thought on Oman in 2025. For south-eastern Arabia he distinguishes and defines Early and Late Iron Ages. In the Sultanate, the Late Iron Age has two facies. The one known from the most sites is designated
Samad Late Iron Age, the other is the "période préislamique récente" which mostly French and Belgian colleagues researched and defined in the United Arab Emirates. Years after finishing the actual report, Yule realised the important publications for the excavations at
al-Akhdhar,
al-Wāsiṭ tomb W1 and other projects. In 2012 the Ministry of Heritage and Culture asked him to document and published an Early Iron Age metal smelting site just inside the
Empty Quarter in Wadi Ḍank,
ʿUqdat al-Bakrah. At the site of
Zafar, capital of the
Himyarite Tribal Confederation, in the Yemenite highlands, field operations continued from 1998 to 2010 with a budget which eventually amounted to 5,300,000 Euros. This project illuminates especially the material culture of the Himyarite period (110 BCE – 525 CE). Yule excavated most notably a 1.70 m high relief-statue depicted wearing a crown which depicts arguably a Christian (Aksumite?) king. He argues that Himyarite culture is not really foreign to
Islam which follows, but actually is a sire which passed on its genes. One wonders what Islamic religion and culture would be like without this influence. Excavated finds contradict the characterisation of Himyarite culture especially visual arts as decadent - a term which can be understood in different ways. Yule considered late pre-Islam in the Yemen to be his most important scientific contribution owing to the opportunity to work for several years and the large number of contested finds. In 2013
Steffen Wenig asked Yule to participate in an excavation project of a church at
Mifsas Bahri in the South Tigray Region. Yule continued this work independently, enabled in 2014 to 2016 by means of a grant from the DFG. This centred on the excavation of a Late
Aksumite church ruin of the 7th century CE. == References ==