Henry E. Catto Jr., 81, a Texas Republican whose party ties and Lone Star charm earned him ambassadorships around the globe, including an appointment to the Court of St. James in England, died Dec. 18 at his home in San Antonio.

He had complications from leukemia, said his son-in-law Daniel Shaw.

In a political career spanning three decades and four Republican presidents, Mr. Catto’s party loyalty garnered him several top government positions. He held the rank of ambassador five times, served as the Pentagon’s top spokesman under Ronald Reagan and was director of the old U.S. Information Agency during the first Bush administration.

Mr. Catto first met George H. W. Bush in Texas during the 1960s, and the two formed a close bond. The 41st president rewarded Mr. Catto’s long friendship with the coveted post in London.

As ambassador to the United Kingdom from 1989 to 1991, Mr. Catto made a distinct impression from the start. To begin his term in England, he formally presented his credentials to Queen Elizabeth II during a ceremony at St. James’s Palace in London.

Mr. Catto, bedecked in white tie, tails and top hat, introduced himself to the royal sovereign by saying: “How ya doin’?”

He flew the Texas flag above the ambassador’s residence, served nachos to visiting dignitaries and planted a plywood cutout of a Hereford cow on the lawn.

“It was my way of saying that the European ban of American beef is naughty,” Mr. Catto told Texas Monthly magazine in 1990.

Although he was sometimes lampooned in the British press, Mr. Catto came to be recognized as an effective ambassador.

In the aftermath of the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland, he met with families of the victims.

Henry Edward Catto Jr., was born Dec. 6, 1930, in Dallas and grew up in San Antonio.

He was a 1952 graduate of Williams College in Massachusetts, where he studied American history.

In 1958, Mr. Catto married Jessica Oveta Hobby, heir to the company that published the now-defunct Houston Post and daughter of William Hobby, a former Democratic governor of Texas, and Oveta Culp Hobby, the first secretary of the U.S. Department of Health, Education and Welfare during the Eisenhower administration.

For several years, Mr. Catto and his wife owned the old Washington Journalism Review, which they donated to the University of Maryland in 1987 and is now known as the American Journalism Review.

Mr. Catto’s wife died in 2009 after 51 years of marriage. Survivors include four children, Heather Kohout of Austin, John Catto of Basalt, Colo., William Catto of Chevy Chase and Isa Catto Shaw of Woody Creek, Colo.; and 11 grandchildren.

In the 1960s, Mr. Catto was running his family’s insurance business when he began to dabble in local politics by running for the state legislature. It was not an auspicious move.

At the time, Democrats dominated Texas politics, and Mr. Catto — against the advice of his father-in-law — ran as a Republican.

Mr. Catto handily lost his election to a Democratic candidate who had been indicted twice, but never convicted, on murder charges.

Mr. Catto’s political fortune changed after bonding with another young Texas Republican on the rise: George H. W. Bush.

Through his friendship with Bush, Mr. Catto became a party confidant and trusted aide to Republican leaders. President Richard M. Nixon appointed Mr. Catto deputy representative to the Organization of American States in Washington, and he later held ambassadorships to El Salvador and the United Nations.

In the mid-1970s, he served as chief of protocol in the White House. In that role, Mr. Catto escorted foreign dignitaries during official visits to the United States.

In 1975, Mr. Catto guided Emperor Hirohito of Japan on a two-week tour of the country, including stops at the Grand Canyon and Disneyland.

“When we would pass a point of interest, I would explain via the interpreter what we were seeing, its history and so on,” Mr. Catto wrote in an 1989 essay in The Washington Post. “After each such expostulation, the emperor invariably said, ‘Ah, so’ — nothing more; no comment, no questions, no exchange.”

One time during the tour, the emperor’s interpreter tapped Mr. Catto and said, “His majesty wishes to tell you something.”

Believing a serious conversation was at hand, Mr. Catto listened intently to the interpreter, who said, “Emperor wished you to know that eggs in United States better than eggs in Japan.”

Mr. Catto replied, “Ah, so.”