は元(もと)よりNot only... but also, Let alone, Of course,

は元(もと)より, commonly seen purely in hiragana, is a grammar pattern that indicates 'not only (A), but also (B) ', or 'let alone (A), (B)'. This construction is just a combination of は, the noun 元(もと) 'origin', and より. In this way, it is just highlighting that 'even compared to the original fact of (A), (B)'. Often, (A) will be something that is considered obvious, or the most well known information in regard to the topic.

はもとより may appear after nouns, or verb phrases that have been nominalized with の or こと.

Alternatively, はもとより may be used in structures where it is simply showing that (A) is the base from which (B) is also a fact. Although this may sound similar to the previous meaning, it translates closer to 'from the start, (A) is (B)', or 'by nature, (A) is (B)'. Which meaning is being used will usually be clear in the context of the overall sentence.