Outgoing Defense Secretary Chuck Hagel said Wednesday during a farewell tribute held in his honor that he is most proud of his time as an enlisted soldier, urging U.S. troops to safeguard the military’s reputation as “the most admired and trusted institution in our country.”

Hagel, speaking to a crowd that included President Obama and other top officials, referred to himself as “this old sergeant.” He joined the Army in 1967, was wounded in Vietnam, and went on to become the first enlisted service member to ever lead the Defense Department.

“We must always protect that confidence and trust by our conduct and performance, continuing to hold ourselves and each other to the highest standards of professionalism and personal behavior,” Hagel said. “As I will soon leave this job that I have cherished, I want you all to know that the things I have most respected and admired are your dignity, your courage, and your dedication.”

The tribute, held at Joint Base Myer-Henderson Hall near the Pentagon, celebrated Hagel for his years of service, both in uniform and as an appointed official. It is widely believed he was forced out of the position due to differences of opinion with the White House, including over how to manage the ongoing military campaign against militants in Iraq and Syria.

On Wednesday, however, he was feted as a faithful servant who has devoted decades to his country. Obama, fresh from a trip to Saudi Arabia and India, called the event a “celebration of a quintessentially American life,” noting Hagel’s time in combat and eventual rise to become a U.S. senator and defense secretary.

“Thanks to Secretary Hagel’s guiding hand, this institution is better positioned for the future,” Obama said. “But Chuck, I want to suggest today that perhaps your greatest impact, a legacy that will be felt for decades to come, has been your own example.

“It’s not simply that you’ve been the first enlisted combat veteran and first Vietnam veteran to serve as secretary of defense, it’s how your life experience — being down in the mud, feeling the bullets fly overhead — has allowed you to connect with our troops like no other secretary before you.”

Obama nominated former Deputy Defense Secretary Ashton Carter to replace Hagel. His Senate confirmation hearing is next week.