This Englishman traveled to Spain and translated many works, including The Elements from Arabic into Latin. He may or may not have had a Greek version to check against; he may or may not have even known Greek. He almost certainly had access to a Latin translation which is now lost to us. We have some manuscripts that appear to be copies of his translation. Arabic words are used for some of the geometrical terms instead of Greek. The main source for his Latin version was probably in Arabic.
Gerhard of Cremona (1114-1187): Wrote many works, among which a translation of The Elements is mentioned by a later writer. Scholars thought that there were no surviving copies of this translation, but now believe that an Arabic to Latin translation found in 1904 is indeed Gerhard's. Again, Arabic terms appear, and it is assumed that his main source was an Arabic version. He also translated many original Arabic works into Latin as well as Arabic translations of Greek originials.
Johannes Campanus of Novara (late 13th Century): Chaplain to Pope Urban IV (who was Pope from 1261-1281). Probably also used an Arabic original, but had access to Athelhard's translation too. This is a very important translation because it was the first to be printed.
Special Note: When we say that someone "probably" had an Arabic original, it means that there is no explicit mention of such a text but that it seems probable or almost certain. Arabic terms appear in some Latin translations, and some of the notes in the margins of the translations indicate at least a knowledge of Arabic versions. A large part of the evidence comes from comparing several versions of The Elements in Latin with one another, with Arabic versions which have survived, and with early Greek versions. Scholars find large and small differences in the text and then draw conclusions about what originals a copyist might have had before him. This is serious detective work, a monumental task. A great deal of intellectual energy has gone into finding out how Classical texts were copied, changed and handed down to posterity.