The Abbasid Caliphate's Rise to Power
Caliphate, the political-religious state comprising the Muslim community and the lands and peoples under its dominion in the centuries following the death (632 CE) of the Prophet Muhammad. Ruled by a caliph (Arabic khalīfah, “successor”), who held temporal and sometimes a degree of spiritual authority, the empire of the Caliphate grew rapidly through conquest during its first two centuries to include most of Southwest Asia, North Africa, and Spain. Dynastic struggles later brought about the Caliphate’s decline, and it ceased to exist as a functioning political institution with the Mongol destruction of Baghdad in 1258.
https://www.britannica.com/place/Caliphate
The first Caliph
The clothing of the Abbasid Era
Abbasid Clothing: The Abbasids were influenced by traditional Arabic dress and Persian court styles. ... The Abbasids loved the public display of wealth. During their time, the rules regulating fabric and design were loosened so the court could wear clothing they felt was appropriate to their ranks.
http://www.12thnight.atlantia.sca.org/wp-content/uploads/2018/10/Abbasid-Clothing.pdf
What is a Hijab?
A hijab (/hɪˈdʒɑːb, hɪˈdʒæb, ˈhɪdʒ.æb, hɛˈdʒɑːb/;
Arabic: حجاب, romanized: ḥijāb, pronounced [ħɪˈdʒaːb] in common English usage) is a veil worn by some Muslim women in the presence of any male outside of their immediate family, which usually covers the head and chest. The term can refer to any head, face, or body covering worn by Muslim women that conforms to Islamic standards of modesty. Hijab can also refer to the seclusion of women from men in the public sphere, or it may denote a metaphysical dimension, for example referring to "the veil which separates man or the world from God."