彼は三人兄弟の長子として育った。
He grew up as the eldest of three brothers.
かつては長子が家督を継ぐのが一般的だった。
In the past, it was common for the eldest child to inherit the family headship.
長子は親の期待を一身に背負いがちだ。
The firstborn tends to bear the full weight of their parents' expectations.