に先立って— Ahead of the Event

• 開会に先立って、市長が挨拶をした。

  Kaikai ni sakidatte, shichou ga aisatsu wo shita.

  Prior to the opening, the mayor gave a speech.

  Noun 開会 (opening) + に先立って marks the speech as a preparatory act before the event

• 新製品の発売に先立ち、記者会見が開かれた。

  Shinseihin no hatsubai ni sakidachi, kishakaiken ga hirakareta.

  Ahead of the new product's release, a press conference was held.

  に先立ち is the more formal continuative form used in writing

• 海外出張に先立つ準備は大変だった。

  Kaigai shutchou ni sakidatsu junbi wa taihen datta.

  The preparations preceding the overseas business trip were tough.

  に先立つ + Noun modifies 準備 (preparations that precede the trip)

• ・Register: formal and written; common in news, announcements, and ceremonies.
• ・Use for significant events, not trivial daily actions — say 食べる前に (before eating), never 食べるに先立って.
• ・に先立ち is the continuative (mid-sentence) form; に先立つ + Noun is the attributive form.

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones に先立って is tested against.

• に際して — On the Occasion Of
• につけ — At Every Turn
• ～にわたって — Spanning the Whole Range
• ～たび(に) — Every Single Time
• ～あげく(に) — After All That, In the End
• ～折(に) — On the Occasion Of
• ～かと思うと／かと思ったら — No Sooner Than, Just When
• ～末(に)／の末(に) — After All Was Said and Done