はもとより

"Not only X (which goes without saying), but also Y." It presents X as the obvious or expected case and adds Y as a further, often broader or less expected, case.

Somewhat formal and used mainly in writing, speeches, guides and news, e.g. describing the reach of places, people or products. It is a more formal counterpart of はもちろん. The first element is presented as self-evident, so the emphasis falls on the added second element.

• 1.
  はもちろんN3「はもちろん」has essentially the same meaning and is interchangeable in most cases, but it sounds more natural and is common in both speech and writing, though less formal than 「はもとより」. It also has the emphatic form 「はもちろんのこと」 and can follow case particles such as 「に」 and 「で」.
• 2.
  はおろかN1「はおろか」 is usually followed by negative or negative-leaning content, emphasizing that even the most basic thing cannot be done, often with surprise, dissatisfaction, or resignation; it is not suitable for positive addition. It can also attach as 「verb dictionary form + の + はおろか」.
• 3.
  のみならずN2「のみならず」 is also written-style language, but it does not require the first item to be obvious; it attaches more broadly to nouns, verbs, and adjectives, and can also be used at the start of a sentence to mean 'not only that'. When the first item is a noun and is obvious, the two are interchangeable.
• 4.
  だけでなくN3「だけでなく」 is neutral in register and, besides nouns, can attach to verbs and adjectives; the first item need not be obvious, and pros and cons can be listed together. In noun sentences, 「はもとより」 can generally be replaced with 「だけでなく」, but the tone is less formal.
• 5.
  に限らずN2「に限らず」 also attaches to nouns and is often followed by 「も」, but it only emphasizes that the scope is not limited to the first item, without the nuance of 'A is obvious' or a progression in degree; it is neutral in register and common in speech. They are interchangeable only when the first item is obvious.
• 6.
  もさることながらN1「もさることながら」 is also written-style language and attaches to noun + も. It acknowledges that A itself is important, with the focus on B or emphasizing that B deserves equal attention; in 「はもとより」, A is merely an obvious premise, and B is an extension in degree or scope.

はもちろん has the same meaning but is more conversational, while のみならず (formal) and だけでなく (neutral) simply mean "not only… but also" without implying X is obvious. はおろか usually appears in negative or undesirable statements, where X is obviously out of reach and even the more basic Y is too (漢字はおろか、ひらがなも読めない); に限らず means "not limited to X," and もさることながら acknowledges X but gives greater weight to Y.