Hello,
It's an anonymous almohad square dirham : coins of this type are undated and don't have the name of caliph on it.
Sometimes we can see a mintname at the bottom but most of them (like yours) don't.
Below are the legends on this coin, written in simple Kufic script. It was struck by the Muwahhid (Almohad) Dynasty (524-668 AH / 1130-1269 AD), but is not dateable beyond that.
Obverse:
لا اله الا الله
الامر كله لله
لا قوة الا بالله
There is no god except God
The whole commandment is unto God
There is no strength except in God
Reverse:
الله ربنا
محمد رسولنا
المهدي امامنا
God is our Lord
Muhammad is our Messenger
Al-Mahdi is our leader
