Somalis especially reer shekh isxaaq goes way back living and trading in Aden, in 1849 number of permanent resident of somali origin was over 2000 somalis.
My family lived in Aden like 3 generations back,i think my 3 grandfather first came to aden before or on 1900,they managed to make a stable business that lasted for 3 generations.
my family still lives in sheekh cuthman area,specifically in Qahira area,somalis indeed used to live like kings back then,the British favored them along with the indians over the yemenis ( b4 the british used to call them just arabs).
A lot reer Caden used to speak Somali or at least understand it, the most famous somali xafado was tawahi, bureeqa,,creter,zacfarana, al mansoorah, qalooca, the later was derived from afsomali ( Qaloocan ) like zigzag road.
even the word xaafa is of somali origin and it is a common word used by yemenis.
during the British colonization,all the administrative posts were only filled by Britons but I remember my family told me the first non-British high officer was a Somali,i think HA, if not mistaken his name was rooble....also one of the most famous masajid in Mucala , masjid alaxmadiya was built by the old somali community ,one of my very distant relatives was the founder of that masjid..sheekh mohamed yusuf,who was a follower of the axmadiya suufism back then.
what I like about reer cadmeed ( reer cadmeed is a term used to denote somalis who were born and raised in aden) is that they are the least qabyalad somalis i ever met, they used to inter marry among each other without any barriers,of course most of them were from somaliland or puntland to lesser extent, things changed though after the doomed yemeni unification and somalia's civil war, the dixbaashi northern regime of ali saleex used to discriminate against yemenis of somali origin, i still remember when one of the northern famous politician in a tv show said publicly that when they came to aden they only found somalis and indians but no yemenis so they have to yemenise the city again.
one of the most famous cadani abwaan is mohamed murshed naji ,ALLAH YERXAMAH ,who was mowalid( father yemeni,mother somali isxaaqi) he never hided his mother was a somali who brought him with bride :
https://www.youtube.com/watch?v=9LWiy8sLdqM