Complex sentence: The quality of his work as a bookbinder brought him into contact with nobility and wealth, and while completing a commission, he was mistakingly attacked, receiving an arm wound that prevented him from working as a bookbinder and led him to concentrate on typography and printing.
Split into simpler sentences: The quality of his work as a bookbinder brought him into contact with nobility and wealth. While delivering a prestigious commission he was mistakenly attacked, receiving an arm wound that prevented him from labouring as a bookbinder and led him to concentrate on typography and printing.