'his gallantry' is a perfectly correct and usable part of a sentence in written English.
It is usually used when referring to a man's chivalry or courage, as in the sentence: "John demonstrated his gallantry when he rushed to the rescue of a small child."
Stuart was noted as the first Anglo-Canadian to receive the Victoria Cross and his obituary later stated that in the action, "his gallantry stood out".
His gallantry will be missed by all.
For that, his gallantry was widely questioned.
His gallantry aided greatly in turning back several counter-attacks".
Once Mr. Belotserkovsky encountered Ms. Ananiashvili's Odette, his gallantry increased.
No newspaper printed his gallantry about the 62-year-old Mrs Albright.
The Tramp's appeal was universal: audiences loved his cheekiness, his deflation of pomposity, his casual savagery, his unexpected gallantry, and his resilience in the face of adversity.
On 30 November, the London Gazette carried the announcement that Minifie had been awarded a Bar to his Distinguished Service Cross as a consequence of his "conspicuous gallantry in air fighting throughout October", that resulted in his personal destruction of "several enemy machines".
He was awarded the Victoria Cross, and the citation read: "His superb gallantry and total disregard for his own safety during an extremely difficult period were responsible for saving the lives of his men and had a decisive influence on the course of the battle".
MacArthur informed the War Department that "Among many outside the immediate staff of this officer, there was criticism of his conduct of operations which while not detracting from his personal gallantry led to grave considerations at one time of his relief from command".
Because the use of Q-ships such as the Prize were still secret, the published details of his award when it was gazetted simply read "In recognition of his conspicuous gallantry, consummate coolness, and skill in command of one of H.M. Ships in action".
